DEVELOPMENT OF THE EGG OF CLAVA LEPTOSTYLA. 225 



the spadix, and that the entire course of development takes place 

 within these walls it is difficult to see how any considerable move- 

 ment of the blastomeres upon each other can be possible. Or, 

 furthermore, how it is possible to have anything like the regula- 

 tion type of cleavage characteristic of the forms just referred to, 

 unless, perchance, the gonophores of C. squainata differ very 

 greatly from those of C. Icptostyla, which hardly seems probable. 

 At any rate, I have not found it possible to trace any close cor- 

 respondence to such features in our species, as will be seen from 

 the following account. 



As stated in an earlier connection, the gonophores of C. Icp- 

 tostyla may contain only a single egg or as many as four, though 

 the usual number is two or three. In many cases where but two 



FIG. 6. Camera sketch of gonophore FIG. 7. Camera sketches of two 



containing two eggs at slightly different eggs, e and/", as seen from side, 

 stages. 



are found they will be upon opposite sides of the spadix, but fre- 

 quently also supported side by side at the terminal portion. In 

 either case the eggs are flattened very much on one or more 

 surfaces, as shown in several of the figures (Fig. 7, c and /). In 

 some cases they may even come to have a biscuit shape, or may 

 be crescentic disks, as also shown in Figs. 3-5. In many cases 

 as the eggs approach full growth there is a tendency to become 

 more or less spherical, especially when occupying singly the ter- 

 minal portion of the gonophore. Now, I have found that these 

 various conditions have a more or less marked effect upon the 

 mode of cleavage. Where the egg is spherical, for instance, 

 cleavage is usually more or less symmetrical, as shown in Fig. 8. 

 On the other hand, where the conditions maintain a continued 



