ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 565 



plant. In a very short time be got a plentiful growth of uredosori 

 developed. He considers that thetecidia may grow on several species 

 of Oxalis, and gives a list of those on which it has been found. 



Water-relation of Puccinia Asparagi.*— Ralph Smith found that 

 the rust of asparagus was peculiarly suited to test the influence of 

 moisture on the infection and spread of the disease. In general the 

 factors that lowered the vitality of the host-plant conduced to the 

 growth of the parasite. When weakened by drought, the asparagus 

 seemed less able to resist the rust, which thus gained from the want of 

 water at the roots of the host. In autumn also the fungus was observed 

 to be more active. Uredospores grew in conditions of moisture, etc., 

 favourable to the fungus ; at other times teleutospores were developed. 

 In reference to the direct action of moisture on the fungus itself, it was 

 found that dew was absolutely necessary to infection and of more im- 

 portance than rain. The author found that teleutospores were a pro- 

 vision for enabling the fungus to survive unfavourable conditions, 

 whether of food-supply, moisture, temperature or resistance by the host, 

 without regard to season. 



Mycoplasma in Uredineae.t — Jakob Eriksson insists again on the 

 endogenous development of the rust of certain cereals. He reviews 

 the work done recently in connection with this subject on Puccinia 

 glumarum and P. dispersa. He affirms the gradual growth of the rust 

 pustule from strands of protoplasm in the host-cell, which form first 

 a protomycelium and afterwards the hyphas of the Uredine. He has 

 found that the " corpuscules speciaux " described before, are endogenous 

 haustoria formed from the fungal protoplasm in the host-cell. 



American Uredinese. — E. W. D. HolwayJ continues his notes on 

 Uredineje already known, and describes a number of new species that 

 have come under his observation. P. L. Picker § also adds one new 

 -species, and gives notes on various forms. W. A. Kellerman|| records 

 the results of his cultures of Puccinia Tlwmpsonii. He inoculated the 

 leaves of Sambucus canadensis with the teleutospores, and got a fine 

 growth of spermogonia and a^cidia. He has thus proved its identity 

 with Puccinia Sambuci. 



Variability of Dictyophora.f — Advantage was taken of a plentiful 

 growth of the common species D. phalloidea to make a series of com- 

 parisons between the different individuals by A. H. Christman. Height 

 varied from 5*6 cm. to 21*2 cm. The taller plants were solitary, and 

 grew in a fairly shaded, moist locality. The size of the collar round the 

 pore was very variable ; the veil also, both in size and structure, pre- 

 sented very great differences. It expanded before the stipe or after it ; 

 sometimes it was a delicate membrane perforated with round holes, or it 

 resembled a net formed of heavy bands with large angular openings. A 

 table is given of the measurements of twenty specimens. 



* Bot. Gazette, xxxviii. (1904) pp. 19-43 (21 figs.). 



t Comptes Rendus, cxxxix. (1904) pp. 85-7. 



X Journ. My col., x. (1904) pp. 103-5. § Tom. cit., pp. 165-6. 



j| Tom. cit., p. 173. f Tom. cit., pp. 101-8. 



