Onchocerciasis in Cattle and Associated Animals. 17 



tralia. 1 They are more frequently flattened like a broad bean in 



the former than in the latter, much as in 0. gnttnrosa, due natu- 

 rally to compression between the muscles and between them and 

 the skin. I have not seen any so large as those sometimes found in 

 O. gibsoni, nor any with anything approaching the great thickness 

 of fibrous tissue, such as occasionally occurs in the latter. A thick- 

 ness of 5 mm. of fibrous capsule is abnormally great in 0. indica 

 in cattle, 2 to 3 mm. being the more common. A larger proportion of 

 nodules of 0. indica seen by me are calcified or caseated, t\ua 

 undoubtedly to the fact that practically only aged cattle are killed 

 in the country whence these come. The whole tissue of the nodule 

 is Often permeated with larvae, even in cases where mature worms 

 show no larvae in the genital tubes; also larvae (.12 to .16 mm. long) 

 are to be found on the periphery of the nodule, and sometimes 

 thickly in the loose connective tissue on the surface of the nodule. 



The connective tissue trabeculae, which form the walls of the net- 

 work of tunnels, in which the worm lies, resemble exactly in nearly 

 every case those of 0. gibsoni, but in two instances (see fig. 4) one 

 was surprised to find within the dense fibrous capsule, which was 1.5 

 and 2 mm. respectively in thickness,- the worm lying quite freely 

 in the interior, with only one or two delicate connective tissue 

 strands 2 to 3 mm. long, in place of the intricate fairly substantial 

 network otherwise present. Evidently either an inexplicable in- 

 hibition of fibroblasts had taken place in the interior during the 

 development of the nodule, or probably, some unusual degenerating 

 factor had been at work, since in one case, the internal structure of 

 the anterior part of the body of the female was almost undecipher- 

 able, while that of the male was also affected. 



The simple relationship found in 0. gibsoni between the heads of 

 the male and the female does not so frequently obtain here. There 

 is always, however, a certain close association (see figure 3), and 

 intertwining of these and of the tail of the male, which are generally 

 to be found on one of the flattened surfaces, the body of the male 

 sometimes coiling about in close proximity at several points to the 

 other flattened side. 



In reference to the numbers of males and females associated 

 together in each nodule, it is interesting to note that although 

 Breinl (p. 9) has noted the occurrence of two males with one female 

 in the case of 0. gibsoni, no one else has hitherto observed this 

 condition, while in 0. indica, of the four females obtained entire, 



1 See Addendum 1, re 0. indica in Bos bubalis. 



