412 BOTANICAL GAZETTE [November 



for study. A young sporophyte, such as is represented in part by 

 fig. 40, shows no differentiation in the sporogenous tissue, though 

 some of the longer cells may be considered as potential elaters. In 

 an older sporophyte (fig. 41) the elaters by their elongation are in 

 sharp contrast with the cells which will produce spore mother cells. 

 In such a sporophyte the protoplasts have contracted slightly 

 from the cell walls, which are still distinctly seen, and the inter- 

 vening spaces are filled with a mucilaginous substance which stains 

 a faint yellow in gold orange. The protoplasts show no difference 

 in their staining, and excepting the difference in shape are alike in 

 general structure. In older sporophytes (fig. 42) the elaters have 

 assumed their characteristic shape, and their protoplasts are under- 

 going the peculiar changes incident to the formation of the spiral 

 thickenings. The walls between the cells are still distinct, but 

 they have lost some of their sharpness, and the mucilaginous 

 substance stands out more distinctly when stained with gold orange. 

 The pronounced irregularity of the shape of the cells which are to 

 produce spore mother cells is a striking feature, and this irregularity 

 continues until the lobed mother cell is fully mature. From the 

 beginning of the differentiation of elater-producing cells and 

 sporogenous cells (fig. 43), the division of the sporogenous cells 

 continues, and frequently lobed mother cells and sporogenous 

 cells still in division are seen in the same capsule. 



Since living material of Symphyogyna could not be obtained 

 to verify the observations made from prepared slides, Pellia epi- 

 phylla, Aneura pinguis, Pallavicinia Lyellii, CephaloziaMcuspidata, 

 and Porella platyphylla were studied. The sporogenous tissue 

 was separated from the walls of the sporophyte and mounted in 

 water, and also other material was studied in the crushed sporo- 

 gonium without the addition of any reagent whatever. The living 

 cells were immediately examined under the microscope, and they 

 were found to show the same irregular amoeboid forms which 

 had been noted in the permanent mounts. Sporophytes from the 

 same material were killed in different strengths of chromo-acetic, 

 with and without osmic acid, and in Benda's solution, and in each 

 case the results showed the same irregularity of the sporoge- 

 nous cells (figs. 56-60). Moreover, in the laboratory all slides 



