92 THE JOURNAL OF BOTANY 



3. Sphcerella botryoides : vesiculis aggregatis, minutis, viri- 

 dibus. Mucor botryoides L., Nostoc botr. Ag., Pahnella botr. Lgb." 



It would, however, be simpler and perhaps equally correct to 

 retain Ghlamydomonas as now used, and to call the second species 

 Sphcerella lacustris. 



Critical Eeferences. 



Sommerfelt, Om den rode Snee, in Mag. f. Naturvidenskab. 

 (1824), vol. iv. p. 249. 



Agardh, Icones Alg. Europ. Nos. 22-4 (1828) (No. 21 is ''Proto- 

 cocmts nivalis "). 



Fries, Samma Vegetabil. Scand. (1849), p. 395. 



Johanson, Svampar fran Island (1884), p. 163. 



Berlese and de Toni, Intorno al Genere Sphcerella, in Atti Eeal. 

 Istit. Venez. (1887), ser. 6, vol. v. pt. 1, p. 221. 



Saccardo, Sylloge Fungorum (1891), vol. ix. p. 659. 



Hazen, The Life History of SphcBrella lacustris, in Mem. Torr. 

 Bot. Club. (1899), vol. vi. p. 211. 



Wille, Algologische Notizen, x. Ueber die Algengattung Sphce- 

 rella Somm., in Nyt Mag. f. Naturvidenskab. (1903), vol. xli. 

 pt. 1, p. 94. 



MALVA SYLVESTBIS L. 

 By E. Adrian Woodruffe-Peacock, F.L.S. 



A CAREFUL study of any given plant should prove useful in 

 suggesting new ways of critically estimating other species. The 

 Common Mallow {Malva sylvestris) will prove as good as any. 



Mr. S. T. Dunn, in his Alie7i Flora, p. 46, writes of it : — "A 

 native of bushy places and pastures in most parts of Europe, but 

 becoming more and more confined to artificial habitats north- 

 westwards in Europe, and in England not recorded in natural 

 habitats, though common on woodsides and about houses." This 

 does not state half the facts now known, nor place them in their 

 proper perspective. It is a simple matter to test the environment 

 conditions of M. sylvestris, which never vary. It demands full 

 sunlight and half shelter from the wind. These two matters must 

 ever.be kept in mind in estimating its nativeness ; they imply that 

 it is a sylvestral species, a frequenter of bushy places. This, how- 

 ever, is by no means all. It is never found in close or open woods, 

 either in England or abroad, so far as I can learn, because there it 

 would be too much cut off from direct sunlight. In pastures it is 

 found in Lincolnshire but only under exceptional circumstances, 

 i.e., in villages and their immediate neighbourhood when pro- 

 tected by nettles, thistles, thorns, &c., where it cannot be got at 

 by stock ; and on roadsides which are slightly or never stocked by 

 cattle it is found abundantly in sunny spots. It apparently flies 

 to man for protection from destructive cattle and sheep. To say 

 it is "more and more confined to artificial habitats" in North- 

 west Europe is to state, in other words, that in our part of the 



