496 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Phoma Disease of Lavender.*— W. B. Brierley publishes an 

 account of this new species, Phoma lavendulse, and of the various culture 

 experiments to test its pathogenicity. On nutrient media the fungus 

 produces hyaline thin-walled pycnospores, thin-walled conidia, which 

 become thick-walled and brown, and thick-walled brown chlamydospores. 

 On the host the mycelium rammifies through all the tissues and produces 

 pycnkUa below the epidermis. Conidial formation is absent from the 

 normal life-cycle, but chlamydospores are occasionally formed. 



Mycetozoa. 



(By A. LoRRAiN Smith, F.L.S.) 



Formation of Sporangia in the Genus Stemonitis.f — A. E. 

 Hilton describes the development of sporangia in this genus from the 

 Plasmodium to the spore stages. The matei'ial which he examined was 

 found on an old stump, covering in patches the blackened remains of 

 an old leathery fungus which grew on it ; it was then in the milk-white 

 Plasmodium stage and in a semi-fluid condition, though in cushion-like 

 form. In about a quarter of an hour after collecting, the cushions 

 were covered with bubble-like hemispheres of uniform size, due to 

 dividing up of the plasm into smaller masses. The first observations 

 had been made at 12 noon ; by 4 p.m. the area covered by the hemi- 

 spheres was contracting ; they were growing taller and assuming a 

 somewhat conical shape, while the lower portions of the mass were 

 becoming columnar. In another half hour black stalks were visible at 

 the centres of the columns. At G p.m. the sporangia were nearly half 

 an inch in height, and at 10 p.m. they had attained their ultimate shape, 

 though still of a light brown or buff colour. By 8 a.m. of the following 

 day they were nearly black ; and by 8 p.m. they were a dark purplish 

 brown. Immediately before the actual formation of spores, the 

 numerous nuclei in the plasm greatly increase in number, each nucleus 

 becoming the centre of an individual spore. 



* Kew Bull., No. 5 (1916) p. 113-31 (2 pis. and 9 figs.). 



t Journ. Quekett Micr. Club, xiii. (April, 1916) 6 pp. (1 pL). 



