Journal of Applied Microscopy. 



637 



and the stubborn extine of 

 the mature spores. It is 

 hard to get Ricciocarpus into 

 paraffin without shrinking, 

 and the same thing may be 

 said of other forms which 

 have such loose tissue with 

 large air cavities. For stages 

 like that shown in the figure, 

 as well as for older sporo- 

 phytes, it will be found more 

 satisfactory to use celloidin, 

 and cut the sections from 

 20 yu to 30 /< thick. How- 

 ever, if nuclear details of the 

 development of spores are to be studied, celloidin sections cannot be cut thin 

 enough, and, besides, they do not allow the stains required in cytological work. 

 Forms like Pellia cut well in paraffin, especially in younger stages, but even in 



iovKP," !^l(.. 



Fig. 5. Pellia epiphylla. 

 Habit sketch of sporophyte. X 10. B. Small portion of sporophyte 

 (at X of A), showing the capsule wall, the spores, and the elaters. 

 Fixed in chromo-acetic acid and stained in cyanin and erythrosin. 

 Ten microns. 



j0UR./)pp.M(C. 



Fig. 6. Anthoceros lasvis. 

 A. Longitudinal section of lower portion of sporophyte imbedded in the gametophyte. X 45- 

 B. Transverse section of lower portion of sporophyte. X 200. Delafield's hamatoxylin. 

 Ten microns. C. Vegetative cell from lower portion of the sporophyte. X 560. 

 Fixed in Flemming's weaker solution and stained in a mixture of acid 

 fuchsin and iodine green. Five microns. D. Spore-mother- 

 cell showing three of the four chloroplasts with numerous 

 starch grains. The nucleus is in the metaphase of 

 the first division. X 560. Fixed in Flem- 

 ming's weaker solution, stained in 

 safranin-gentian violet-orange. 

 Five microns. 



case of mature sporophytes it is not necessary to resort to celloidin. In Pellia 

 and Conocephalus the spores are very large and have a rather thin wall. Both 

 these genera show a peculiar, intrasporal development of the gametophyte, i. e., 

 the gamethophyte develops to a considerable extent before it ruptures the spore 



