58 SUMMARY OF CURRENT RESEARCHES RELATING TO 



terminal ; the penial setse differ from tliose of T. orientalis by having 

 wavy ridges round the distal portion, and there are only two genital 

 papillae. 



The author discusses the structure and homologies of the so-called 

 prostate glands in the Oligochfeta, and comes to the conclusion that the 

 so-called prostates of Pericliaeta are equivalent to the atria of Acantho- 

 drilus, Pontodrilus, and others; in Monoligaster BarwelU the atrium 

 consists of a thick glandular covering of peritoneum, of a layer of 

 muscular fibres, and of a single layer of columnar epithelium. 



Reproductive Organs of Eudrilus.* — Mr, F. E, Beddard has a 

 further communication on this subject. He finds that a pair of 

 problematic bodies in the thirteenth segment have their duct com- 

 municating with the duct of the spermatheca. These bodies were 

 regarded as being probably ovaries, and this view is supported by 

 Eosa's description of a pair of similar structures which are placed 

 in an identical situation in Teleiidrilus, and contain nearly mature 

 ova, and by the author's discovery of numerous mature ova in these 

 bodies in Eudrilus. But, while the tube by which the ovary in the 

 thirteenth segment in Eudrilus communicates with the exterior is a 

 real duct, lined by a single layer of columnar cells, the tube which 

 leads from the ovary to the receptaculum in Teleudrilus is simply a 

 ccslomic sac. Eudrilus appears to have another pair of ovaries in the 

 fourteenth segment, and its oviduct, on either side, opens opposite to 

 that of the thirteenth into the spermathecal duct. Each ovary is 

 enveloped in a muscular sheath which is continuous with the oviduct, 

 and this investing sheath is probably equivalent to the receptaculum 

 ovorum of other earthworms. 



j3. Nemathelminthes, 



' Nematode in Blood of Dog-.f — Br, P. Sonsino has made a study of 

 the life-history of Filaria hsematica (Gruby and Delafond) or F. immitis 

 (Leidy), which is found in the blood of the dog. It occurs in the heart, 

 pulmonary artery, subcutaneous tissue, intermuscular connective, &c. 

 The young stages are passed in one of the epizoic parasites, whence the 

 adolescent form returns to the dog. In this the history of Teenia 

 cucumerina is paralleled. It is hardly just to regard Spiroptera or 

 Filaria sanguinolenta as a true hsematozoic parasite. Besides F. immitis 

 there may be in the dog other haematozoic nematodes, which like it 

 propagate their embryos in the blood and have similar external inter- 

 mediate hosts. The parasites may be acquired, according to Galeb and 

 Pourquier, during foetal life from the mother. From the young dog 

 thus infected from the first, the nematode embryos may pass secondarily 

 to the epizoic parasites. 



The author then describes the rare nematode Bictularia plagiostoma, 

 obtained from a new host, the fox. Like its previously known hosts, the 

 bat and hedgehog, the fox was probably infected by eating insects. 

 Both sexes are described. Embryos were seen within the eggs contained 

 in the oviduct — the worm is " ovoviviparous." The peculiar chitinous 

 appendages are carefully described, those of the male are more uniform 

 than those of the female. Other species of Bictularia are discussed, 



* Zool. Auzeig., xi. (1888) pp. 643-6. f Arch. Ital. Biol., x. (1888) pp. 190-6. 



