56 KINGSLEY. [Vol. I. 



ommateal and the ganglionic portions of the eye. Fig. 13 shows 

 these features well, but it must be borne in mind that in it the 

 region of the crystalline cone is exaggerated in order to show 

 the surrounding cells. 



The subsequent growth of the ommateum can readily be un- 

 derstood without a figure. The retinophorae continue the 

 secretion of the crystalline cone and with the growth of this 

 portion of the eye the nuclei of the cells are forced from their 

 present position. Those of the retinophorae are driven to 

 occupy a place on the ends of the crystalline cones while pig- 

 ment-cells I and 2 are forced to take a much deeper position 

 and the filamentary terminations of all the pigment-cells (the 

 bacilli) become much more slender. This is especially the case 

 with the outer or distal ends of these organs. The deposition 

 of pigment continues and extends in each cell as far as the outer 

 layer of nuclei. In the lower ends of the retinophorae, where 

 they unite to form the pedicle the changes are obscure. The 

 pedicle becomes gracefully swollen and is separated from 

 the calyx by a slender style. In the interior of the pedicle ap- 

 pear (how, I know not) curious cross bands (vide Patten, '86, 

 PI. xxxi., Fig. 72.) In the ganglionic regions the changes are 

 but slight and of the same character as those already described. 

 There is an increase in the number and size of both ganglia and 

 the intermediate fibrous portions ; and in some way fibres come 

 to cross the optic cavity, a filament going from each ganglionic 

 row to the corresponding pedicle. How these arise I am not 

 able to say, nor have I seen that complex arrangement of the 

 fibrillae and the nerve terminations described by Dr. Patten. 

 I have, however, been able to trace the axial nerve through the 

 pedicle and style and into the distal portion of the crystalline 

 cone. The character of this axial nerve, together with theo- 

 retical considerations, render it probable that it is an outgrowth 

 from the ganglionic portion of the eye. 



The changes which occur in the optic cavity are considerable, 

 but I have not satisfactorily traced the steps. The cavity be- 

 comes greatly expanded, so that it eventually measures half the 

 width of the ommateal portion of the eye. The mesoderm con- 

 tained in it becomes correspondingly developed and apparently 

 forms a neurilemma which sheathes each nerve-fibre crossing the 

 cavity, and in which there is a considerable deposition of pig- 



