208 



Colchicine 



Fig. 8.3 — Origin of strophosomy in chicks. Injection of colchicine in the eggs at 48 hours 

 of incubation. A. Control at the time of injection. B. Control, incubated 72 hours. C, 

 D. Colchicine-treated embryos, incubated 72 hours. These are future strophosomes, as 

 indicated by the backward flexion of the tail. E, F. These chicks, similarly treated, will 

 only develop celosomy. The tail is bent forward. (After Lallemond'') 



known to exist in calves, which may be born strophosomic after an 

 intra-uterine growth of normal duration. 



The caudal bending of the embryo appears quite important, and 

 it is to be noted that pycnotic nuclei arising from arrested meta- 

 phases are to be found in this region, mainly in the nervous system 

 and the smroiuiding tissues. Neither the chorda nor tlie intestinal 

 epithelium shows evidence of cellular destruction. 



