ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 261 



The resting-cells divide into zoogametes 8 jx long by 5 /a broad, which 

 move about with great velocity, and are provided with four cilia, 

 distinguishing them from the other species of the genus. 



Oosperms resulting from the fusion of zoogametes, the author states, 

 differ in no essential point from those produced by oospheres and an- 

 therozoids ; indeed, Eudorina may, under exceptional circumstances, 

 produce its oosperms in the former way instead of the latter. 



The author reaffirms his previous conclusion that the Chlamydo- 

 monadinese and Euglenese must be regarded as families of Algae rather 

 than of Protozoa, and expresses an opinion that normal chlorophyll is 

 to be found only in organisms belonging to the vegetable kingdom. 



Fungi (including' Lichenes). 



Physiological Significance of Mycorhiza.* — In opposition to the 

 views of Hartigf and Grosglik, Herr B. Frank reaffirms the view that 

 the phenomena of mycorhiza are of the nature of mutual symbiosis, and 

 that the fungus is in no true sense a parasite on the root of the tree 

 which it attacks. 



The mycorhiza depends for its existence and subsistence, not on the 

 root of the tree, but on the presence in the soil of undecayed vegetable 

 matter. The fungus behaves like a haustorium or absorbing organ, the 

 hyphfe radiating on all sides like root-hairs ; they may be isolated or 

 united in fascicles, giving to the root the appearance of a bottle-brush. 



Trees, the roots of which are infested with mycorhiza, resemble 

 such saprophytes as Neotiia nidus-avis in not exhibiting a trace of 

 nitrates ; while trees which are not attacked by it contain nitrates, at 

 least in their absorbing roots. It is most probable that the mycorhiza 

 removes nitrogen from ammonia and organic nitrogenous substance, and 

 thus enables the tree to obtain nitrogen in the same way that saprophytic 

 fungi do ; and the fungus on the other hand receives equal benefit from 

 the mutual symbiosis. 



Hibernation of Peronosporese.l — Herr P. Magnus states that the 

 hibernation of the mycele when oosperms fail to be formed, which, in 

 Phytophthora infestans takes place in the tuber of the potato, is effected 

 in Peronospora effusa in the rosettes of young leaves of the spinach on 

 which it is parasitic, and in P. Alsinearum in the stem and leaves of the 

 autumn shoots of Stellaria media. 



Entomophthorese and their use in the destruction of noxious 

 Insects. § — Si. C. Brongniart states that the Entomophthorese are very 

 widely spread in nature, and that they cause certain and rapid destruction 

 to a great number of noxious insects. All locusts are rapidly attacked 

 by these fungi, death resulting in about twenty-four hours after the first 

 indication of the attack. On these insects Entomoj)]ithora is found 

 under two forms which were formerly considered as two distinct genera, 

 Emjpusa and TaricMum. Empusa fructifies in the interior of the body, 

 and produces conidial spores, while TaricMum consists of the oosperms 

 which are formed also in the interior of the body. The author considers 



* Ber. Deutsch. Bot. GeselL, vi. (1888) pp. 248-69 (i pi.). Cf. this Journal, 

 1888, p. 268. t Cf. this Journal, 1886, p. 662. 



X Verhandl. Bot. Ver. Prov. Brandenburg, xxix. (1888) pp. 13-5. 

 § Comptes Rendus, cvii. (ISSS) pp. 872-4. 



