582 EXPEEIMENT STATION EECORD. 



typical nodules were discovered in calf (a). No evidence can be adduced re- 

 garding the mode of infection. 



"The housing arrangements of calves (c) and (d) were such that biting 

 and flying insects had ready access to the animals, and as the distance from 

 the infected cows was not great we can certainly assume that these biting and 

 flying insects had good opportunities for infecting the calves. The fact that 

 they were not affected during the seven to eight months' period of exposure to 

 possible insect vectors apparently indicates that the intermediary host is not 

 a biting or flying insect, and even an ordinary skin parasite, o. g., Hypodcrma 

 tuberculatus, which travels a short distance, may be eliminated. 



"The negative result of this experiment as also [that to ascertain the r61e 

 played by insects in carrying O. r/ihsoni] points to the probability of the inter- 

 mediary host of O. gibsoni being on the ground. Both pens were floored with 

 concrete ; the experimental calves had no chance of lying on or near the ground 

 where infected cows had previously laid. It seems to us to indicate that part 

 of the life history of the parasite is spent on the ground. 



" Since these experiments were finalized, we have received Cleland's report 

 on his further investigation into the etiology of worm nests in cattle [E. S. R., 

 32, p. 377]. We note his remarks on the possibility of Stormoxijs calcitrans or 

 CvUcclsa vigilux acting as intermediary hosts of 0. ^gibsoni. In the liglit of our 

 knowledge here and in view of tlie results of the exiieriraents conducted at the 

 laboratory, we can not add support to his contentions." 



Investigations into the occurrence of onchocerciasis in cattle and asso- 

 ciated animals in countries other than Australia, Geokgina Sweet (Mel- 

 bourne: Govt. [1915], pp. 53, pis. 7; abs. in Trap. Vet. BuL, S (1915), No. Ji, pp. 

 130-133). — The present paper is based upon investigations made during the 

 course of an extended tour of the world. Tlie worm nodules In the connective 

 tissues caused by species of Onchocerca, now known to exist in cattle and asso- 

 ciated animals, are listed in tabular form, as are the allied parasitic worms 

 present, as previously known, in the main aorta» of cattle and buffalo. 



" The new species herein described from cattle in India, while overlapping 

 in some respects the allied species Onchocerca gibsoni and O. gutfurosa, differs 

 from those in the association in the male worm of a certain range of length of 

 the larger spicule intermediate between those two species, with a greater num- 

 ber of differently arranged anal papillre than is found in either of them, and 

 from O. gibsoni further in the thicker head of the male, the thinner head and 

 tall of the female, and the generally longer esophagus in both. 



" The limitations of these species appear to be geographical rather than 

 otherwise, thus. 0. giitturosn is characteristic of northern Africa, presumably 

 in Bos taiirus; 0. indica is found in B. indieus in the peninsula of India; and 

 O. gibsoni in B. indieus in the Malay Peninsula and as a very variable form 

 in B. taurus in Australia, and most probably the Malay Archipelago. The oc- 

 currence of such nodule-forming worms is probably much wider than is at 

 present suspected." 



A bibliography of 34 titles is appended. 



Complement fixation in hog cholera, D. .1. Heat-Y and W. V. Smith (Jour. 

 Infect, ni-'fcases, 17 (1915), Xo. 1. pp. 2I3-21S). — While working on the etiology 

 of hog cholera at the Kentucky Experiment Station the authors have obtained 

 an antigen from the mesenteric glands of acute cholera hogs which shows strik- 

 ing differences in its reaction toward normal hog, rabbit, and cow sera and 

 hyperimmune hog serum. This antigen is not removed from the extract by 

 passage through an ordinary porcelain filter, but is removed by passage 

 through the "F" bougie. The antigen is not found in the freshly prepan^ 



