WORM NODULES IN AUSTRALIAN CATTLE. 335 



seventeen, up to thirty-two celled stages being observed ; the 

 nuclei in the latter stages becoming smaller and more oval or elliptical. 

 This fully-formed morula or mulberry stage is sometimes common. 

 In the next stage normally the embryo loses the oval form and as- 

 sumes the almost comma-like stage (fig. 19) found in the develop- 

 ment of various other nematode eggs, though here the tail of the 

 comma is very much less pointed than in such forms as Agchylostoma 

 duodenale or Ascaris lumhricoides. Also we have been unable to 

 detect any such definite difference in size of the nuclei at the two 

 poles, such as is found in some forms, for example, Stephanurus 

 dentatus. Successive stages to this (for example, figs. 20 to 25) 

 show a gradual elongation and narrowing of the protoplasmic body 

 of the parasite, this increased length being compensated by a more 

 or less involved coiling of the embryo, which, however, usually 

 comes later to lie in a less complicated manner. The comparatively 

 few large nearly spherical nuclei of the morula and comma stages 

 become converted by rapid division, so that in the stage repre- 

 sented by figs. 22 and 23, in which the well-marked outline is clearly 

 present, there may be as many as six rows of nuclei. The diminish- 

 ing size and increase in number of the nuclei is shown in the figures, 

 which are all drawn by camera lucida. It will be noted from the 

 figures that in this development there is no division of the general 

 protoplasm into ceils corresponding to that of the original nucleus 

 into the numerous nuclei of the later stages. The protoplasm with 

 its nuclei forms at first an oval syncytium, which becomes much 

 elongated into a tliread-like syncytium. 



In some smears, however, obtained on different occasions, 

 some strange and puzzling appearances were noted. The first of 

 these suggests itself as being a stage immediately succeeding the 

 morula stage, and shows the oval syncytium, the nuclei being 

 arranged in a definite convoluted chain, as represented in fig. 26. 

 A number of similar eggs were noted on several occasions. The second 

 appearance [see fig. 27) shows a lobulated protoplasmic mass with a 

 tendency to convolution, of bands of much smaller nuclei, and might 

 be regarded in some way as intermediate between fig. 26 and figs. 

 24 or 25. The change in structure is apparently due to the longi- 

 tudinal and transverse division of the nuclei forming the single 

 chain just described, the form of a coiled chain of nuclei now much 

 smaller and more numerous being retained in a more or less definite 

 manner. In the light of present knowledge we cannot but regard 

 these two apparent stages in the development as at least abnormal. 

 If they be not artifacts, which there is no reason to believe they are, 

 then the oval syncytium of the morula stage in these cases must 

 have become converted into the coiled solid cord or protoplasm 

 which forms the fully developed embryo by division and arrange- 

 ment of the nuclei and an aggregation of the protoplasm around 

 them, the latter splitting in the lines between these linear aggrega- 

 tions of nuclei and protoplasm. So far as we are aware such a 

 method of development is unknown in any other animal, and we 

 cannot yet regard it as a normal method of development. The 



