158 



Prof. H. Marshall Ward. 



mid-grandparent to grandchildren. The coefficient of correlation was 

 0*272 ±0-12, and the coefficient of regression = 0*5 ±0*2, while, accord- 

 ing to theory, they should be 0*3 and 0*6 respectively. 



The evidence of these measurements cannot be said to be conclusive, 

 and I am about to test the theory on some other parthenogenetic 

 animal. If, however, this kind of inheritance be found to hold at all 

 generally in parthenogenesis, it would be a fact of very considerable 

 significance, and might conceivably give some insight into the physio- 

 logical causes of heredity and variation. 



" Onygena equina (Willd.) : a Horn-destroying Fungus." By H. 

 Marshall Ward, D.Sc, F.K.S., Professor of Botany in the 

 University of Cambridge. Eeceived April 6, — Eead May 4, 

 1899. 



(Abstract.) 



The genus Onygena comprises half a dozen species of fungi, all very 

 imperfectly known, remarkable for their growth on feathers, hair, 

 horn, hoofs, &c, on which their sporocarps appear as drum-stick 

 shaped bodies 5 — 10 mm. high. A cow's horn, thoroughly infested 

 with the mycelium of the present species, yielded material for the 

 investigation, and the author has not only verified what little was 

 known, but has been able to cultivate the fungus and trace its life- 

 history, neither of which had been done before, and to supply some 

 details of its action on the horn. 



The principal new points concern the development of the sporo 

 phores, which arise as domed or club-shaped masses of hyphse and 

 stand up into the air covered with a glistening white powder. Closer 

 investigation shows this to consist of chlamydospores, formed at the 

 free ends of the up-growing hyphse. Their details of structure and 

 development are fully described, and their spore nature proved by 

 culture in hanging drops. The germination, growth into mycelia, 

 and peculiar biology of these hitherto unknown spores were followed 

 in detail, and in some cases new crops of chlamydospores obtained 

 direct in the cultures. 



When the crop of chlamydospores on the outside of the young 

 sporophore is exhausted, the hyphse which bore the spores fuse to 

 form the peridium clothing the head of the sporocarp, and peculiar 

 changes begin in the internal hyphse below. 



Minute tufts or knots of claw-like filaments spring from the hypha? 

 forming the main mass of the fungus, push their way in between the 

 latter, and so find room in the mesh-like cavities. Here the closely 

 segmented claws form asci — they are the ascogenous hyphse — and the 



