INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 923 



classification of the Mucorini or Zygomycetes into two sub-families, 

 one clistinguisliecl by sporaugial, the other by conidial non-sexual 

 fructification. 



Beech Disease, Phytophthora Fagi-* — Professor Hartig finds 

 that this disease of young beech-seedlings is spread by the oospores 

 which germinate in the soil. The mycelium differs from that of other 

 Pcronosporefe in being septated. The mode of formation of the 

 sporangia is similar to that described by de Bary in the case of 

 Phytophthora infestans. The germinating filaments of the zoospores 

 creep along the surface of the leaf, and j)enctrate between the ejiidermal 

 cells, sporangia beiug produced in the course of two or tliree days. 

 The mycelium and sporaugia develop chiefly in the cotyledons, much 

 less luxuriantly in the foliage-leaves. 



The formation of oospores takes places as follows :— On the inter- 

 cellular mycelial filaments are formed numerous not very long lateral 

 byphfe, which swell up into a club-shaped form, producing oogouia at 

 the extremity. The oogonium is thin-walled, filled with protoplasm, 

 and is divided off from the hypha by a partition wall, beiug thus 

 elevated on a short stalk. In the neighbourhood of each oogonium is 

 produced at the same time a much smaller antheridium by the swelling 

 into a club-shaped form of the apex of a hyphal branch, which usually 

 becomes attached to the oogonium near its base. The wall of the 

 oogonium not unfrequently exhibits an indentation at this spot ; but 

 the coalescence of the two sexual cells consists simply in a union of 

 growth, and the resorption of the substance of the wall of the oogonium 

 at a small round spot; there is no forcing itself of the antheridium into 

 the oogonium by means of a beak-like process. The contents of the 

 antheridium, which is divided off from the hypha by a septum, then 

 pass over into the oogonium; the protoplasm of the oogonium some- 

 what contracts, and an oospore is produced, at first with a thin, after- 

 wards with a very thick wall. The oospores may either germinate 

 directly, or tliey may retain their power for at least three years. 



The disease has at present nearly confined its attacks to nurseries, 

 where the young plants are very crowded. The practical remedy 

 appears to be to refrain from planting the seed in soil likely to be 

 infected with the oospores. 



Berggrenia— New Genus of Discomycetes.t — Dr. Cooke describes 

 an aberrant genus of the Discomycetes which possesses a general 

 interest to the mycologist as a new arrangement or inversion of 

 organs. The fungus was collected in 1874-75, by Berggren, of Lund, 

 during his visit to New Zealand, and the name Berggrenia is proposed 

 for it. It is ovate, pyriform, somewhat clavate, about one inch in 

 height, and nearly as much in breadth, but compressed laterally to 

 one-fourth of that thickness in one direction. It looks very much 

 like a Tremella, being a little plicate or rubbed below and inflated, so 

 that the centre is hollow, and though attenuated a little at the base 



* ' Forstwissenschaftlicbes Centralblatf,' i. (1879); see 'Bot. Zeit.,' xxxvii. 

 (1879) p. 511. 



t A paper read by Dr. M. C. Cooke at tbe annual meeting of the Woolhope 

 Club, at Hereford, October 2, 1879; see 'Gardeners' Chronicle,' 1879 (Oct. 25) 

 p. 533. 



