204 Mary Isahelle Steele 



uous band and reestablishing the broken connection between the 

 muscle and the chitinous covering of the stalk. 



Fig. 57 of the same series represents a section deeper in from 

 the dorsal surface so that parts of the optic ganglion are apparent. 

 A few scattered spots of pigment are also present. Here again 

 the regenerated tissue shows differentiation into strands of fibers in 

 the part lying beyond the remains of the old muscle band. In 

 other regions there is a loose network of fibers with scattered nuclei. 

 A difference, however, in the appearance of the nuclei in different 

 regions of the regenerated tissue can be observed. From a lo h 

 the nuclei are small and inconspicuous, constituting uniformly 

 granular masses and staining with but little more intensity than 

 the fibers which extend inward from them. The nuclei lying 

 between the points b and c, on the contrary, are conspicuous, stain 

 deeply and are more than twice the size of those lying between 

 a and b. Here also a number of nuclei are seen lying below the 

 periphery which show a tendency to extend straight inward from 

 the periphery. Fig. 58 shows the upper part of a section that lies 

 so near the ventral surface that it is entirely outside most of the 

 optic ganglion. In this figure no part of the muscle band appears. 

 Conspicuous masses of pigment are present in this section as well 

 as a great number of relatively large deeply staining nuclei. 

 Since the eye was cut longitudinally from the dorsal to the ventral 

 side the sections near the ventral side are approximately tangential, 

 so that many of the nuclei that appear to be deep in from the 

 periphery are in reality near to the surface. This needs to be 

 kept in mind in interpreting the figures. 



It is a conspicuous fact that many of the nuclei shown in Fig. 58 

 resemble in shape and appearance the retinular nuclei found in 

 sections of regenerating eyes. Further resemblances between 

 these and retinular nuclei are their tendency to stain deeply and 

 the general direction of their long axes which is at right angles to 

 the surface. These facts considered in relation to each other 

 leave but little doubt that these elongated nuclei represent the 

 retinular elements in a regenerating eye. At one point in Fig. 37 

 (c.c.) the rudiments of two crystalline cones have appeared. This 

 is additional evidence that an eye is regenerating, imperfect and 



