Some Saprophytic Fungi of Potatoes. G. H. Pethybridge. 117 



for three years, no reproductive organs, other than conidia and 

 chlamydospores, were ever observed. 



A considerable number of inoculation experiments were 

 carried out with these two species on living potato stalks and 

 tubers. In no case did infection occur and there was no indica- 

 tion of any ability to invade or grow in the vessels of the wood 

 such as characterises the parasitic V. alho-atrum. 



The characters of these two species may be summed up as 

 follows : 



Verticillium nubilum Pethybridge. 



Mycelio albo effuso ; ramis fcrtilibus ascendentibus, verticil- 

 latis; conidiis continuis, oblongatis, hyalinis, magnitudine 

 varia plerumque 9|U.x3/x; hyphis in matrice submersibus 

 chlamydosporis moniliformis vel conglobatis subglobosis, atris 

 8-5-12 yLt diam. 



Hah. In tuberis putrescentibus Solani tuberosi, in Hibernia. 



Verticillium nigrescens Pethybridge. 



Mycelio albo effuso ; hyphis fertilibus erectis, ramis verticil- 

 latis ; conidiis hyalinis, continuis, oblongatis, magnitudine varia 

 plerumque 7/Ltx2/x; mycelio in matrice submerso, chlamy- 

 dosporis terminalibus, vel lateralibus, vel intercalariis, aut 

 globosis, circ. 4-3 fi diam., aut sub-ovalis, circ. 6^t x 4/x atris. 



Hab. In tuberis scabiosis Solani tuberosi, in Hibernia. 



V. LANGLOISULA MACROSPORA A. L. Sm. 



When examining blighted potato foliage in the search for 

 possible oospores of P. infestans, isolated brown spores were 

 again and again met with, the origin and identity of which 

 were not clear. The same spores have also been met with on 

 blighted tubers. 



No difficulty was experienced in getting a pure culture from 

 these spores, and the resulting fungus was identified by Mr. J. 

 Ramsbottom and Miss A. Lorrain Smith as Langloisula niacro- 

 spora by comparison with type material in the British Museum. 

 This species was described in 1901 by Miss Smith* who found 

 it spreading over a grass seed in the germinating case. 



On agar media the submerged mycelium is hyaline and 

 about 3/x thick. Over the surface of the medium much larger 

 hyphae about 9/x thick run, and from these conidiophores arise 

 here and there in more or less isolated tufts or balls. The 



* Sniilh, A I-orrain. Fungi found on farm seeds when tested for germina- 

 tion; with an account of two Fungi new to Britain. Journ. Roy. Microscop. 

 Soc. 1901, p. 617. In the description in the text the species-name heterospora 

 is given but this is probabl}' a misprint for the name macrospora which is 

 apphed to the iigures on tlie accompanying plate and wliich is given to the 

 fungus in the account pubHshed in Trans. Erit. Myc. Soc. i. 1902, p. 194. 



