No. 2.] THE DEVELOPMENT OF THE NEWT. 319 



sist of camera drawings of eggs seen in different positions. 

 Each cell has its own individual number in order to facilitate 

 recognition in the different points of view. The eggs chosen 

 for this study were those especially favorable specimens which 

 permitted identification of the first two cleavage planes. They 

 are therefore to be regarded as more regular than the great 

 majority of newts' eggs, since in most cases the first two 

 planes cannot be recognized with any fair degree of certainty. 

 In the eggs I have chosen to represent there is a minimum 

 of uncertainty. The lines indicating the first two planes 

 are printed more heavily than are the others. Since the 

 magnification of all figures on this plate is the same, 

 the series from Fig. 26 to Fig. 32 serves to illustrate 

 the considerable variation in size of the newt's &^^. The 

 size appears to be in the main dependent on the size of the 

 female, the larger individual as a rule depositing the larger 



Figs. 26A-26D represent an Qgg of eight cells seen in 

 different positions. 26A is a view from the upper pole, 26B 

 and 26C are views from the side, and 26D is from the bottom 

 of the ^g%. The general disposition of the cells is very re- 

 mote from the usual eight-cell stage, one cell — 3 — extend- 

 ing all the way from the upper to the lower pole. Figs. 27A- 

 27D are views of an Q^g of a more advanced stage, 27 A and 

 27D being respectively the upper and lower poles. The two 

 upper right hand octants, 3-4 and 5-6, have divided in diagram 

 fashion from the intersection of the first two planes, but the 

 other two, 1-7 and 2-8, have divided at very different angles. 

 Only one of the lower pole cells (Fig. 27C, 9-12) has begun to 

 divide. Figs. 28A-28D show a still wider departure from the 

 orthodox type of cleavage. The upper pole (28A) presents a 

 far from regular appearance. Figs. 29AI-29D picture the 

 most regular ^^^ of this stage that I was able to find. Even 

 here the lines of the third vertical do not start from the inter- 

 section of the first and second planes. Figs. 30A-32B illus- 

 trate top and bottom views of three eggs in advanced stages of 



1 The upper pole of this egg bears a close resemblance to the egg figured by 

 Rauber ('83) in Fig. 35, PI. XII. 



