480 WM. E. KELLICOTT 



4. The effects of the low temperature which may be actually 

 observed in the treated individuals, take the form of irregulari- 

 ties in the distribution and combinations of both nuclear and 

 cytoplasmic substances, and in the formation of cell-walls. 



5. The results obtained by this method are essentially similar 

 to those already known to follow chemical treatment and hetero- 

 geneous hybridization. 



6. It is suggested that the cause of abnormal and monstrous 

 development here and in other similar instances, is to be found 

 in a disturbance of the normal organization of the ovum, as 

 expressed by the unusual characters and distributions of the 

 differentiated materials of the egg protoplasm. 



7. This 'disorganization' hypothesis seems to afford a better 

 explanation of many instances of abnormal and monstrous 

 development among the vertebrates, than does the current 

 'nutrition' hypothesis, which is in many particulars opposed by 

 the results reported here. 



