THE EFFECTS OF LOW TE:MPERATURE UPON THE 



develop:\iext of fuxdulus 



A CONTRIBUTION TO THE THEORY OF TERATOGENY 



W^L E. KELLICOTT 



From The Marine Biological Laboratory, Woods Hole, and the Biological Labora- 

 tory, Gaucher College 



There have recently appeared several embryological contribu- 

 tions of importance, based upon the development of the familiar 

 minnow, Fundulus heterochtus. Stockard ('09, '10, '13) and 

 more recently Werber ('15, a) have described a large number of 

 abnormal and monstrous embrv^os resulting from chemical 

 treatment of the fertihzed eggs and have made several sugges- 

 tions regarding the modus operandi of the treatments used and 

 the causes of monstrous development. And in the works of 

 Stockard ('15) and Reagan ('15) advantage is taken of the pos- 

 sibiUty of causing, also bj^ chemical treatment, certain embry- 

 onic abnormalities, in attacking a group of mooted questions 

 in normal embryogeny and histogenesis. 



Dm'ing the smnmer of 1915, at The ^Marine Biological Labora- 

 toTv, 1 was able to cany out a rather extended series of experi- 

 ments on the production of monstrosities in Fundulus by a 

 method which involved no direct chemical stimulation and which 

 thus permits me to test certain pre^'iously suggested causes of 

 abnormal development in the species studied. The method is 

 so simple and so mai'kedly effective that it seems desirable to 

 make a brief report upon it and to point out its bearings upon 

 the general theories of teratogeny, although at this time I shall 

 not attempt to give an extended analysis either of the precise 

 results obtained or of the exact mechanism of the disturbance of 

 normal development. 



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