462 WM. E. KELLICOTT 



My own findings reported here certainly tend strongly to 

 confirm the idea that the causes underlying abnormal develop- 

 ment are to be sought in some derangement of the fundamental 

 developmental mechanism or relations of the diverse compo- 

 nents of the very early stages of the ofganism. In the first 

 place it should be noted that by using a low temperature as the 

 abnormal stimulus I have eliminated the necessity of supposing 

 that there are any specific chemical alterations, such as precipi- 

 tating or solvent effects, due to the use of chemical stimuli,- 

 which is so important an element of Werber's hypothesis. 

 There may be some osmotic changes in the cooled eggs and there 

 certainly is an increase in oxygen tension, but McClendon ('12) 

 was unable to find that such conditions affected the frequency 

 of cyclopia in Fundulus. On the other hand some of the effects 

 of cold may be directly observed in the eggs during treatment, 

 so that the character of the disturbance is not wholly left to be 

 inferred from the study of later development. 



As mentioned above, eggs which were placed in the refrigera- 

 tor within a few minutes after insemination were found, some 

 days or weeks later, whether a few cleavages had appeared mean- 

 while or not, to contain at least three classes of materials. 1) Not 

 only nuclei of the usual appearance but also irregular, large and 

 small masses and fragments of nuclear material scattered indis- 

 criminately through the cytoplasmic parts of the egg. There 

 were ordinarily no cellular outlines corresponding with these 

 masses of nuclear substance. 2) Masses of granular cytoplas- 

 mic substance somewhat resembling the material of the greater 

 part of the normal uncleaved germ-disc. 3) Masses of clearer, 

 possibly protoplasmic substance usually in the form of vacuoles, 

 slightly resembhng in physical appearance that mass of clear 

 cytoplasm that in normal development forms, for a brief period 

 preceding cleavage, a lens-shaped disc on the lower side of the 

 central part of the germ-disc. I am not yet in position to iden- 

 tify these forms of cytoplasmic substance with the two chief 

 forms observable in normal development; but the similarity is 

 suggestive. Eggs in this state are still capable of some sort of 

 developmental process when returned to ordinary temperatures, 



