In a previous paper (1934) it was shown that the life-cycle of S. trachea proceeds best when an intermediate host is involved. By means of Eisenia foetida, an annulate worm, it was possible to induce heavy and certain infestations of gapeworm in chickens with material obtained from the partridge, pheasant, rook and chicken. Other earthworms were shown to be possible intermediate hosts but this was found to be the best and most successful.

In a note in the British Medical Journal for February 3rd, 1934, there is mention of the anthelmintic action of garlic oil. One paragraph says that good results have been obtained in the treatment of threadworm in children while a second is more specific and quotes the case of a woman who was cured of Ascaris lumbricoides in 36 hours. She passed a male, 13¾ inches long, a female and a bunch of newly hatched young.

For many years past, Syngamus has been recognised as a serious trouble in both avian and mammalian hosts, and the course of the disease has been closely followed in several birds of economic importance. The symptoms are well known and have often been cited. Clinically the first symptom to appear is a characteristic sneezing and coughing in the affected bird. This is followed later by the best known symptom—the actual gaping—when the bird stretches its neck and opens its beak widely in its endeavour to ease respiration. There are minor signs such as a general debility with ruffled feathers but these are secondary and not specific to this disease. Internally in the trachea there is an increase in the secretion of mucus, which coupled with the presence of the gapeworms is sufficient to cause asphyxiation and the bird dies.

Early in June, 1933, the writer received two vials of caterpillars, to which nematodes were attached, from Mr. A. M. Adamson of the Pacific Entomological Survey with a request, supported by Mr. E. P. Mumford, the Director of the Survey, that an examination and identification of the helminths would be much appreciated.

Early in 1934 the writer received from Prof. Mario Curzi of Rome an agar tube culture on which were growing, in addition to bacteria and a fungus belonging to the genus Fusarium, a number of nematodes which Prof. Curzi wished to have identified. The majority of the nematodes proved to belong to the genus Cylindrogaster whilst the others were found to be Aphelenchus avenae Bast.

1. The preparation of a cercarial antigen from infected livers of Oncomelania hupensis the intermediate host of Schistosoma japonicum in China is described.

2. The sera of 49 human beings and five dogs have been investigated for the Schistosome complement fixation reaction, using as antigens Bilharzial cercarial antigen, and an alcoholic extract of the livers of Oncomelania hupensis infected with cercariae of S. japonicum.

3. Thirty-seven of the 49 sera examined were from cases of Schistosomiasis, and of these 24 gave a positive complement fixation reaction, and 2 others a weak reaction.

4. Of the five dogs examined three were infected with Schistosoma japonicum. These gave positive reactions.

5. In 24 cases both antigens were used, and the results obtained were almost identical.

6. The Bilharzial antigen was used in 33 cases including 25 cases of Schistosomiasis, of which 19 gave a positive reaction.

7. In 40 cases the Oncomelania antigen was used. This series included 32 cases of Schistosomiasis of which 23 gave a positive reaction and 3 a weak positive reaction.

8. Negative results were obtained with 50 strongly positive Wasserman sera, and with 2 cases of infection with Fasciolopsis buski, and two cases of Clonorchis sinensis. Ascaris and hookworm infestations also gave negative results.

The study of populations of animals has received the attention of a large number of workers. Of these, however, but a few have been interested in the problem in its application to parasitic nematodes and in this field there is consequently a limited literature. Particularly is this so when the parasitic nematodes of sheep are considered, the incentive for study of which, in most cases, has been the pressing need for their destruction. This desire has been fulfilled to a greater or lesser degree, but at the expense of researches which would have contributed to a more fundamental knowledge of the ecological relationships of parasitic worms in general.