Science, whose high aim it is to investigate Nature, to under stand her secret workings, and thus to win for man the mastery of Nature, must set out with the conviction that Nature is intelligible, comprehensible, and conquerable. In the domain of biological science the problem of heredity occupies a position of great importance, one full of interest to every student of life. For the serious thinker who has not only looked backwards and studied the past of the human race but is inspired by ideals and desires for its future good, the subject of heredity provides an inspiring theme for contemplation and study. The development of our knowledge and the history of human endeavours to reach a complete understanding of the phenomena and conditions of heredity form one of the most interesting chapters in human evolution. Theories of heredity, like theories regarding other phenomena of life, have been expressed in three sets of terms: theological, metaphysical, and scientific. It required no skilled observation of early man to see that in the act of fecundation the male furnished the seminal substance, whereas the female seemed to furnish nothing except the receptacle or “mould,” in the form of the womb, within which the fótus was formed. Thus, what was more natural than to suppose that heredity was solely paternal, that the male element was the germ or seed, and the female organs the soil, in which, by some mysterious process, growth and development of the germ took place. This view of heredity has been expounded in the Manava Dharma-Sastra, one of the ancient sacred books of the Hindus (Delage, L'hérédité, 1903, p. 380). The same view, more or less modified according to the prevailing state of knowledge, was current among the ancient Greeks (Eristratos, Diogenes, and others). Galen and the school of philosophers of Alexandria also upheld the doctrine of the paternal factor of heredity, and thus constituted themselves the school of the Spermatists. Spermatist views prevailed for many centuries, and when towards the close of the seventeenth century Leeuwenhoeck discovered the presence of spermatozoa by the aid of the microscope, the spermatists had a season of rejoicing. Hartsoeker (1694) supposed that within the spermatozoon there was a little being, a human being, in miniature, with all its parts and organs complete, and figured a spermatozoon (highly magnified, of course) in which the little “homunculus” is to be seen seated within the “head” of the former with its arms and legs folded together in small compass, somewhat like a fcetus in utero. The theory of the spermatists was not destined to remain in undisputed possession of the field. The rival school of Harvey in the sixteenth century taught that the semen or sperm did not fertilise the ovum nor even enter the womb, but that it fertilised the entire constitution of the mother by a sort of contagion which rendered her capable of acting as the stimulus of development for the ova in the uterus, and Descartes, in the early part of the seventeenth century, entertained the same views. The ovists now claimed that all the organs of the future being already existed, preformed in miniature, in the ovum, as opposed to the spermatists, who claimed the same preformed structure for the spermatozoon. To the ovists, therefore, the act of fecundation was only an impulse or stimulus to development communicated by the male element to the ovum; the male contributed nothing material in forming the parts and organs of the fótus which existed, preformed in the ovum, so that the child was the product of the mother alone. Among the upholders of the ovist theory, in the eighteenth century were Malpighi, Haller, Bonnet, and Spallanzani. Difficulties, however, arose over both these theories of exclusive inheritance, for the ovists could not explain how the offspring sometimes resembled the father rather than the mother, and the spermatists could not account for cases of close resemblance between the mother and offspring, while neither could, again, account for cases of the mixed or blended resemblance of the offspring to both parents. The theory of preformation gradually lost its interest and its vitality, and received its death-blow at the hands of Wolff (1759), who, not only by theoretical arguments but by indisputable facts as to the nature and process of development of the hen's egg, demonstrated the baselessness of the fancies of the pre-formationists, whether of the spermatic or ovarian school. Finally, there gradually grew up in the nineteenth century the modem view that the male and female (germ and sperm) cells of the respective parents contributed in equal, or nearly equal, proportions to the constitution of the embryo, and that the environment and nourishment of the fertilised ovum during its growth and evolution in the womb was a third factor of importance, especially in the case of those animals which went through a long period of intra-uterine growth and evolution, as in the case of man and the higher mammals.

The more modern and advanced opinion of the present day, not of necessity the most correct, regards toxic action as the most important factor in the pathogenesis of insanity. According to this view insanity is not regarded as primary disease of the brain, but secondary, and due to toxins derived from elsewhere acting upon the cortical nerve-cells, disordering their metabolism, and thus affecting their functional activity, damaging, or destroying them. The older psychologists are evidently disinclined to accept the toxic theories of the younger school, and cling with pertinacity to their opinion that mental disease is as a rule primary, and that the physical manifestations of ill-health result from a disordered central nervous system, and undoubtedly many of the facts they produce in support of their argument are difficult to refute; on the other hand, it is necessary for those who advance the theory of toxaemia as the essential factor in the production of insanity to marshal facts supporting their contention. By the term “auto-intoxication” we indicate toxins evoked within the body as a result of disordered metabolism, first, such as takes place in chronic Bright's disease, myxcedema, diabetes, etc.; and secondly, in the contents of the gastro-intestinal tract. Within the limits of this paper I propose only to deal with the second division, viz, auto-intoxication from the gastro-intestinal canal, for the cases coming under this group are by far the more numerous and important. For a long time I have strongly held the opinion, as a result of my own observations, that a very large proportion of cases suffering from melancholia are due to auto-intoxication resulting from the absorption of toxins from the alimentary tract, for in depressed states generally there are various symptoms referable to disordered metabolic processes in some part of the gastro-intestinal tract. The symptoms in question that I consider as evidence of a state of toxaemia are as follow: foul breath, coated tongue, indifference to and often refusal of food, marked constipation, foul stools, anaemia (varying in degree), a sallow dirty skin, profuse perspirations and of offensive odour, skin irritations, eruptions, disorders of sensation, often leading to flesh-picking, and headache. Of course we do not in any one case find all these symptoms, but there are several common to all cases of acute melancholia. It may be suggested that the signs and symptoms that I have mentioned as those of toxaemia are but those of lowered general health, and do not in themselves afford any direct evidence of the absorption of toxins, but I have observed that the signs and symptoms that I refer to as constituting toxaemia so commonly present in states of mental depression are constantly associated with the presence in the urine of indoxyl, in greater or lesser excess.

It is currently admitted that the state of intoxication in neuropathic persons differs from that of normal individuals or of habitual drunkards. Of this peculiar state Bonhoeffer has lately given an excellent account, but when one attempts to gain a clear conception of it the clinical cases scarcely bear out the general description. It will, therefore, perhaps be not inappropriate to go over some cases of this pathological form of intoxication which are not yet numerous and endeavour to gather them into a more definite group.

In the last number of this JOURNAL, I gave reasons for concluding that the table of forms of insanity, suggested by the Statistical Committee, was unsatisfactory, and suggested a new classification of cases of insanity to be substituted for their arrangement. Certain objections that are likely to be taken to the classification that I have proposed are worth considering, and would have prolonged the previous communication to an unwieldy length if embodied therein; I propose, therefore, to consider them now.

Normal humanity has never taken kindly to the idea of annihilation. As far back as anthropology has pushed its researches traces of a belief in a survival after death have been found. We have but to open the tombs of the men of the neolithic period to discover idols, mystic symbols, traces of food and clothes, with which our far-off progenitors sought to express their belief that the dead still lived and were open to the ministries of pious affection. The truth is, the thought of annihilation is too abstract to be intelligible to the primitive mind. Wordsworth's “little maid” could not conceive death except in terms of life, and her inability is a universal mark of undeveloped thought. Savage man has no knowledge of death as a fact or process of nature, only as the product of some hidden and malevolent energy which, though it may destroy, cannot annihilate. The dead are not really dead. They haunt the spot which on earth they loved, mingle with the dreams, and affect for good or evil the fortunes of the living. Out of this instinctive impulse, through the growth of mental faculties and the reaction of environment, have been gradually evolved the lofty hopes of religion and philosophy.

Excluding debtors (who are non-criminal prisoners), a local prison is one containing persons charged with an offence awaiting trial, or convicted and serving a sentence of imprison ment of less than two years. A convict prison contains con victed prisoners sentenced to three or more years' penal servitude. All prisoners sentenced to penal servitude have been while awaiting trial, or are for a short time after sentence, detained in a local prison, and thus come within the cognisance of the medical officer there.

My paper will not be a lengthy one, and should perhaps be prefaced with an apology. For it contains no new facts, nor have I the results of any investigation to communicate.

When any belief tends to reappear in various races from age to age and under various conditions of civilisation and education, it acquires a special interest because it probably depends on some general trait in the mental organisation of our species.