LABORATORY STUDIES 253 



(c) Place a spore-case under tlic microscope and examine 

 with a low power, noting the lid. Now remove the lid and 

 observe the teeth. The teeth may be studied still better by 

 splitting the spore-case from base to apex and then mounting 

 in alcohol, and afterward adding potassium hydrate: or the 

 lid may be removed and a transection of the si)ore-case made 

 just below the peristome, so as to show the latter from above. 

 In these specimens spores may be studied also. 



{(I) Split a young spore-case and examine the external sur- 

 face of the lower part for breathing-pores, and note internally 

 the adjacent chlorophyll tissues, and the sporogenous layer 

 above. 



(e) Collect a number of mosses not in fruit, showing at the 

 apex of their stems little cup-shaped whorls of leaves. IVIake 

 several vertical sections of one of these cups, and mount in 

 water. Examine for antherids and archegones. Sperms may 

 sometimes be seen with a high power. 



(/) The first stage (protonema) of a moss gametopl\vte may 

 be found by scraping off some of the greenish growth from a wall 

 or cliff or surface of a greenhouse flower pot where yomig mosses 

 are just springing up. By mounting some of this in water and 

 washing awaj^ the dirt the branching green growth may 

 generally be seen, with here and there the buds which give rise 

 to leafy stems. 



LITERATURE OF BRYOPHYTA 



D. H. Campbell, The Structure and Development of Mosses and 

 Ferns, New York, 1905. 



L. AI. Underwood, Descriptive Catalogue of the Xorth American 

 Hepaticae, Champaign, 1883. 



L. Lesquereux and T. P. James, Manual of the Mosses of 

 North America, Boston, 1884. 



A. J. Grout, Mosses with a Hand Lens and Microscope, Brook- 

 lyn, 1905-1911. 



