600 MK. S. LE M. MOORE S STUDIES 



The chloriodide of zinc method is quite inapplicable to this case, 

 from the violent swellings which that reagent causes ; for the 

 same reason it is impossible to stain the threads with aniline 

 dyes. The subepidermal cell-layers have thicker walls than have 

 the other species of the genus. As is the case with 8. lynatia, 

 so here prolonged use of chloriodide of zinc serves to demonstrate 

 continuity up to the epidermis. 



Mr. Gardiner* has discovered continuity in the endosperm of 

 a large number of seeds referable to mauy of the natural orders ; 

 but with the exception of Tamus and Dioscorea, which have un- 

 pitted endosperm, communication is established through the wall 

 at the bottom of pits. The endosperm of at least two species of 

 Diospyros (embryopteris and melanoxyloii) greatly resembles that of 

 Strychnos Nux-vomica ; dry sections near the surface show a 

 number of round lumina lying apparently in a homogeneous 

 matrix ; but if sections be cut in planes near and parallel to either 

 of the three planes mutually at right angles which roughly divide 

 the seed of D. embryopteris into symmetrical halves, the cells 

 composing the core of the endosperm will be seen to be greatly 

 elongated. Placed in water the contour of the cells becomes 

 more or less evident, but the walls swell up only to a slight 

 extent, and that slowly. In this case the method of demonstra- 

 tion invented by Gardiner, with the slight modification already 

 mentioned (p. 597), was resorted to — indeed, it is the only one 

 which will satisfactorily bring the threads into view. Sections 

 were placed in chloriodide of zinc for several hours (usually about 

 a day) ; they were then removed and examined in this condition, 

 or washed until disappearance of the brown stain, and dyed with 

 picric blue. Figure 11 shows one of the cells with round lumen 

 and its connections with its neighbours as seen before, and fig. 12 

 another as seen after, the action of the dye. One remarkable 

 point about this is the difference in the number of the connecting 

 threads ; close to such a state of things as is drawn at fig. 12 one 

 may find cells intercommunicating by means of a much larger 

 number of threads. As this cannot be clue to incomplete stain- 

 ing, since precautions were taken to ensure saturation with the 

 dye, one cannot but conclude that the threads are apt to become 

 obliterated. The protoplasm of the long cells is also connected 

 with that of the neighbouring cells on all sides (fig. 13). Con- 



* Phil. Trans, memoir. 



