ANDROGENESIS 



179 



Fertilization of the egg and the removal of the female nucleus (androgene sis) in Triturus 

 viridescens. 



Fig. 1 



Fig. 2 



Fig. 1. Drawing of an egg in its capsule about 12 minutes after deposition, showing two dark 

 sperm marks and the lightly pigmented polar area containing in its center the second 

 maturation spindle, marked by a small pigmented spot. 



Fig. 2. Diagram of the pipette, needle, and an egg in position for puncturing. 



Androgenetic embryos of Triturus viridescens compared with control and younger diploid 

 embryos. 



Fig. 3 



Fig. 4 



Fig. 3. 



Fig. 4. 



Androgenetic embryo 7 days old (b), the diploid control of the same age and from 

 the same female (c), and a younger diploid embryo (a), of about the same stage of 

 development as the androgenetic embryo. The head and eye vesicles of the andro- 

 genetic embryo are smaller than those of either one of the two diploid embryos. 



Androgenetic larva 12 days old (a), the diploid control of the same age of (c), and 

 younger diploid larva (b), of about the same stage of development and from the 

 same female as the androgenetic larva. The differences in the size of the gills as 

 well as the size of the pigment cells of the haploid and the two diploid larvae are 

 very noticeable. The haploid larva is also shorter than both diploid larvae. 



(Kaylor, 1937: Jour. Exp. Zool. 76:375) 



