Onchocerciasis in Cattle and Associated Animals. 1~) 



append in Tables 6 and 8, the measurements made of the worms 

 found in these Siamese and Malayan nodules. One nodule from the 

 Indian bullock was particularly interesting, as it was found to eon- 

 tain two females. 4 iv. and 4 v., and three male worms, 4 i., I ii. 

 and 4 iii. No. -'5 was also from the same animal, Nos. I and 2 being 

 from the Siamese bulls. Also, in Table 7 and Figure 10, I have 

 show T n the number and arrangement of the anal papillae, which are 

 emphatically not those of O. indica, and which vary considerably 

 among themselves. It is interesting to note in Fig. 10 (3, left side) 

 one solitary and unilateral example of four adanal papillae (cf. the 

 usual four adanal papillae of 0. indica), though even here the total 

 number of papillae is only seven on that side. 



CONCLUSIONS. 



It is evident then that we have in India itself a different species 

 of nodule-forming worm from that present in the same host species 

 in Siam and Malaya, and in Bos taurus in Java and Australia. 

 The exact geographical limitation of 0. indica, I am unable to state 

 further, and it is more than possible, as hinted before, that with 

 additional material from Burma and Bengal, or elsewhere, one may 

 find a complete mergence of the one species into the other in view 

 of the remarkable extent of variation in each, but especially in 

 O. gibsoni, and of the already known overlapping in some measure- 

 ments. Still there is the most definite and constant means of 

 separation in the association of a shorter long spicule, with a 

 smaller number and different arrangement of anal papillae in O. 

 gibsoni. 



It would appear that 0. indica is the true species of the Peninsula 

 •of India, and 0. gibsoni as seen in these Siamese and Malayan 

 cattle that of the Malay Peninsula, and immediately adjacent coun- 

 tries. Further, either (1) the 0. gibsoni seen in Australian cattle and 

 that of the Malayan and Siamese cattle are undergoing a process 

 of modification parallel with one another, from 0. indica, or (2) 

 O. indica has arisen from the Malayan 0. gih&oni; or (3). and 

 most probably, both 0. indica and the Malayan 0. gibsoni have 

 arisen together from the original form, and from this Malayan 

 form either directly or indirectly the Australian form (introduced 

 at least 70 years ago) has continued to be modified, its variability 

 being quite remarkable. Although the greater length of the large 

 spicule of 0. indica is fairly constant, and its shorter length in the 

 Malayan 0. gibsoni is likewise fairly constant, the anal papillae 



