ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 363 



Azolla in British Isles. — A. S. Marsh gives the history of the 

 occurrence of Azolla in the British Isles and in Europe generally. Two 

 species — A. caroliniana and A. filkaloides — have been- introduced into 

 Europe. A.Jilicnloides is a hardy South American species, distinguished 

 by its dense tufted habit and by its shoots often protruding above the 

 surface and not lying flat. It is much larger and thicker than 

 A. caroliniana, with a more compound and denser ramification. The 

 upper lobes of the leaves have a broad distinct margin and bear uni- 

 cellular trichomes. The reproductive organs ripen in November and 

 afford the most distinctive characters, the glochidia of the massulse of 

 microspores having non-septate stalks, and the macrospore-wall being 

 marked with large deep circular pits. 



A. caroliniana, on the other hand, is a' half -hardy species, ranging 

 from Lake Ontario to Brazil. It is smaller, lies flat on the surface of 

 the water, is less branched, has fewer rootlets, and the margin of the 

 upper leaf -lobe is not as broad as in A.Jilicidoides. The glochidia have 

 3-5 transverse septa in the stalk, and the macrospore-wall is only finely 

 granulate, but the fructification is very rare indeed. A. caroliniana was 

 first recorded in Europe in 1872, and in England in 1883. It has been 

 recorded from the Thames Valley, the Norfolk Broads, etc. But Osten- 

 feld pointed out in 1912 the second species, so all records need revision. 

 Marsh says A. filicidoides is much the commoner species, and he has 

 seen true A. caroliniana from Enfield and Godalming only. A. fili- 

 culoides was introduced into Europe in 1880. 



New Papuan Ferns.f — E. B. Copeland publishes descriptions of 

 seventeen new species of ferns collected by the Rev. C. King, of Ambasi, 

 Papua, showing the points of morphology and structure by which they 

 are characterized. He also defines Holostachyum, a new subgenus of 

 Af/laomorpha, to receive a few New Guinea species in which the fronds 

 are completely dimorphous and not simply provided with a specialized 

 fertile upper portion. 



Bryophyta. 

 (By A. Gepp.) 



Fruit-bearing Receptacle of Marchantiese.J — R. Douin describes 

 the development of the fruit-bearing receptacle of the Marchantieae, of 

 which there are two quite different types. 1. The receptacle with a 

 furrowed or canaliculate peduncle, as in Reboulia, Grimaldia, Fimbriana, 

 Peltolepis, FeyateUa. This arises from the apical point of the thallus 

 and prevents further growth of the main axis. 2. The receptacle with 

 peduncle not canaliculate, which either (1) arises from a special vegeta- 

 tive point immediately behind the apes of the thallus, as in Clevea and 

 Plagiochasma ; or (2) from one branch of the bifurcating apex, as in 

 Lunularia. The Marchantieae may thus be divided into two groups 

 analogous to those of the Jungermannieae, namely (1) anacrogynous 



* Proc. Cambridge Phil. Soc. ; svii. (1914) pp. 383-6. 

 t Philippine Journ. Sci., ix. (1914) (Bot.j pp. 1-9. 

 X Comptes Rendus, clviii. (1914) pp. 1435-S. 



2 b 2 



