PLATE XXXVIII. 



Fig. 1. Cap of Ctciiolabrus. [pb = periblast). Osmic 15m. (3^%), Merkel 3ds. Same age a.s [in 



(2) Fig.] 2, but not quite so far advanced, i. e. the nuclei of [marginal] row are somewhat elongated, 

 and in a few cases faint asters are seen at the poles of the nuclei, but no striation is visible in 

 the nucleus. 



The entoblastic wreath is characteristically granular and thins out rather abruptly into the 

 pellicle, just beyond the nuclei. The cells on both sui-faces of cap were distinct. The cell- 

 boundaries around these [wreath] nuclei were visible here and there, but very faint as shown 

 in figure. Now and then a nucleus of a second inner row — just under edge of blastoderm — is 

 seen. Here also the nuclei are mostly elongated in a radial direction. 



Color: — Wreath and pellicle colored slightly with carmine, but the cap browned with osmic. 

 The contrast between granular pink wreath and light brown cap is striking here as in all cases 

 thus treated. 



Fig. 2. Cap of Ctenolabrus. [pb = periblast). Seen from outer surface three hours after the .32- 



(1) cell stage is reached. To the cap adheres the entoblastic wreath, which is thickest at the edge 

 of cap, gradually thinning out towards the periphery, which is ragged in consequence of being 

 broken from the pellicle. This wreath is stained faintly with carmine (borax alcohol) while 

 the cap is browned by osmic acid and not stained by carmine. The wreath reaches under the 

 cap for a short distance but not to the central parts of cap. There is a single row of nuclei, 

 radially placed (some tangential and oblique), and all in process of division, mostly showing a 

 well-marked nuclear plate in different stages of division, and asters (rather faint). The cell 

 outlines about the nuclei are not visible, except in a few instances. Most of the nuclei of the 

 ectoderm are round; one is seen in division, and beneath it is a nucleus of the endoderm-wreath 

 in division. Although there is, broadly speaking, only one row of nuclei visible, an inner row 

 makes itself apparent in several places and now aud then a nucleus (dividing) may be seen just 

 under the edge of the cap. 



