-SO SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the seeds of the host-plant, and published his research as a thesis 

 presented at Wabash College, Crawfordsville, Indiana. He distinguishes 

 two classes : (1) those which infest the seed internally as in anthracnose 

 of beans, Ascochyta Pisi on pea, and some smuts ; (2) those diseases 

 where the fungus spore becomes attached to the mature seed 

 externally, as in most of the smuts, in some rusts, etc. Some bacterial 

 diseases are also propagated in this way. Advice is given as to cleansing 

 of seeds. 



A disease of melons and cucumbers,* first recorded and described in 

 America, has appeared in Gloucestershire. It is due to a small Ascomy- 

 cete which attacks and kills the stem and the leaves ; these wither and 

 die. Only the conidial (Ascochyta) stage has been noticed in England, 

 and it only occurs in hot-houses. 



T. Johnson f publishes further observations on Spongospora Solani, 

 the powdery potato scab. He has had opportunities of examining 

 Berkeley's Tuburcinia scabies, formerly considered as a smut, and finds 

 that it is identical with his specimens of Spongospora. Potato crops in 

 the Scilly Islands and Cornwall have suffered from the disease this 

 summer, where it appeared in a very destructive form. Johnson 

 describes again the development of the fungus, and proves its identifica- 

 tion w T ith the one described by Wallroth in 1842 as Ergsibe subterranea. 

 Johnson finds that treating scabby tubers for 18 to 20 hours with 

 Bordeaux mixture kills the disease and insures a healthy crop from 

 these tubers. 



An account J comes from Kew as to the extent to which the above 

 Potato scab has spread throughout the country. Most of the cases 

 reported are from Scotland, the worst area being the Hebrides. Soil 

 does not seem to be a factor of great importance ; the fungus is propa- 

 gated from diseased tubers. Rhizoctonia violacea also attacks potato 

 tubers, and when the mycelium penetrates the tissue it reduces it quickly 

 to a pulp. Another disease, Hgpochnus Solani, reported from Birken- 

 head, attacks the haulm just above the ground level. From St. Helen's 

 in Lancashire, cases of potato leaf blotch were sent to be examined. 

 The foliage was attacked by a hyphomycetous fungus, Sporidesminm 

 Solani f. varians, which forms brown patches on the leaves. Spraying 

 with half strength Bordeaux mixture is recommended, and, in autumn, 

 the burning of all diseased tops. " Sprain " in potato tubers was also 

 investigated. It is accompanied by brown spots in the flesh of the 

 tubers ; in some of them mycelium was found. In some cases the 

 brown spotting is an incipient stage of winter-rot. 



Sybil Longman § has also been working on potato disease to deter- 

 mine the nature and cause of dry-rot. This is due to Fusariiim Solani, 

 which spreads more particularly among stored potatoes. It is a true 

 parasite, and if diseased tubers are planted the fungus travels to the 

 shoot, causing them to shrink and die. Longman describes the 

 mycelium as forming pink, white, or buff-coloured mycelium with typical 



* Journ. Board Agric, xvi. (1909) pp. 579-80. 



.t Sci. Proc. Roy. Dublin Soc, xii. (1909) pp. 165-74 (3 pis.). 



% Journ. Board Agric, xvi. (1909) pp. 642-8 (1 pi.). 



§ Journ. Linn. Soc, xxxix. (1909) pp. 120-9 (1 pi.). 



