No. 2.] THE DEVELOPMENT OF THE NEWT. 309 



Born finds that in Triton taiiiatiis the first polar body is expelled while 

 the &%g is in the upper part of the oviduct. I had strongly suspected that 

 this was the case in Diemyctyhis (see p. 307), but was unable to present 

 definite proof. Born's results on this important point furnish a welcome 

 confirmation of my surmise. 



I do not feel it necessary to enter at this time into a fuller discussion of 

 the minor points of accord and discord between Born's results and my c \vn, 



III. Fertilization. 



The fertilization of the ^gg takes place just before the egg" 

 is extruded. The spermatozoa, which have long been in wait- 

 ing in the tubes of the receptaculum seminis, are either 

 attracted from their resting-places by the passing ^gg or forced 

 out by contraction of the surrounding muscles. I have made 

 repeated and careful search for spermatozoa in the oviducts, 

 but have never succeeded in finding one. Neither have 

 I ever found in sections any indication that spermatozoa 

 enter oviduct eggs, although eggs often lie for some time in the 

 mouth of the oviducts. Fertilization, then, would seem to 

 take place only after the Qgg has left the oviduct and passed 

 into the cloaca. 



It sometimes happens that non-fertilized eggs are droppedl 

 by females in captivity. It is an interesting fact that these 

 non-fertilized eggs are not deposited in a carefully prepared 

 nest, but are dropped, apparently without concern, on the 

 floor of the aquarium. Sometimes, but very rarely, an Q:g^ 

 thus loosely dropped develops normally, showing that fertili- 

 zation has taken place. The explanation of the dropping of 

 non-fertilized eggs seems to be that in females with full ovi- 

 ducts, an Q.gg is occasionally pressed into the cloaca by the 

 mere elasticity of the oviduct walls and without the special 

 cognizance of the newt. This ^gg then passes out like so 

 much excreta without the performance of a voluntary act of 

 oviposition. The fact that these eggs are, for the most part,, 

 unfertilized indicates an expulsion of spermatozoa from the 

 receptacle during the normal process of egg-laying. This view 

 is strengthened by the fact that the act of oviposition usually 

 takes an appreciable time, often eight or ten minutes, pointing 

 to essential accompaniments of the mere process of extru- 



