ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 335 



of lime in the Boulder Clay is inimical to the occurrence of Sphagnaceae 

 on that stratum. 



Flora of Kew Gardens. — E. 8. Salmon * gives a list of 109 species 

 of mosses and 7 varieties collected in the Royal Botanic Gardens, Kew, 

 in 1897-8. Most of these he considers to be truly wild ; others found 

 only on the rockery were probably introduced on stones from Cheddar 

 and Bath ; and a few on stems of tree-ferns are exotic. Notes on 

 critical and peculiar forms are added. C. H. Wright f adds a list of 15 

 hepaticEe, 8 of which occur in fern houses and pits, 4 on the rockery, 

 and i\ in the open ; and 3 of them are exotic. 



New Form of Orthotrichum cupulatum.f— C. Meylan describes 

 a new form of this variable species under the name of sub-species 

 0. juranum. He has found it on dry rocks facing N. or N.W. on the 

 summits of the Jura Mountains. He regards this sub-species as of equal 

 rank with 0. nudum and 0. sardagnanum. The peristome teeth are 

 always split, almost, sometimes quite, to their base, and the dorsal and 

 ventral surfaces of these teeth are very finely striate, sometimes almost 

 smooth, or finely papillose. Other constant characters are noted, and a 

 detailed description of the sub-species is given. A key to the four 

 sub-species of 0. cupulatum Hoffm. shows the constancy and value of the 

 respective characters of each. 



Germination of Moss Spores.§ — P. Becquerel gives the result of his 

 experiments in the germination of the spores of Atrichum undulatum 

 and Hypnum velutinum in different sterilised liquid media. He comes 

 to the conclusion that all the morphological differences of the protonema 

 depend much more on the species, age, light, exhaustion of food supply, 

 and aquatic or aerial media, than the different chemical compositions of 

 the three liquids in which the plants were grown. After about 7 or 8 

 months of existence the plant may throw out spherical cells in which the 

 protoplasm and the nucleus surround themselves by a thick cellulose 

 membrane, and await a favourable opportunity for further division. 

 This condition is attributed by the author to age or to exhaustion of the 

 food-supply. The distribution of light has a considerable influence on 

 the germination of the spores and on the position of the primary axes 

 of the protonema, especially in Atrichum. Finally, he states that aerial 

 and liquid media have an exactly opposite effect one to the other. The 

 former encourages extreme development of the protonema and dis- 

 courages, or even arrests, the formation of buds. The liquid medium 

 restrains the growth of the protonema and hastens the production of 

 both buds and rhizoids, the latter imbibing nutriment from the liquid. 



Sexuality of Spores in Dioicous Mosses. || — A. Gilkinet gives a 

 resume of a paper by E. and E. Marchal, in which the following two 

 questions are discussed : 1, whether or not all the spores of one and the 

 same moss-capsule are of the same sex ; 2, whether the protonemas are 



* Kew Bull., add. ser., v. (1906) pp. 91-100. t Tom. cit., pp. 101-2. 



* Rev. Bryolog., xxxiii. (1906) pp. 3-5 (figs in text). 

 § Rev. Gen. Bot., xviii. (1906) pp. 49-66 (8 figs.). 



|| Bull. Classe Sci. Acad. Roy. Belg., 1905, pp. 638-41. 



