630 SUMMARY OF CURRENT RESEARCHES RELATINCx TO 



subject during the year 1908. The sections are headed : A. Pathological 

 plant anatomy ; B. General plant pathology ; C. Special plant patho- 

 logy ; D. Plant hygiene ; E. Plant-therapy ; F. Advancement of phyto- 

 pathology and plant protection. Diseases caused by animals as well as 

 by fungi are included in the survey so far as they have been noted or 

 studied during the year. The literature of each subject is given at the 

 end of the chapter dealing with it, and also at the beginning of the 

 sections, and there is a full general index to the whole volume. 



American Text-book of Plant Diseases.*— B. M. Duo-oar has in- 

 eluded m his account of plant diseases the work done in recent years in 

 the different agricultural stations throughout the United States. He 

 gives a brief historical account of the subject. The general text of the 

 book falls into three parts : (1) culture methods and technic ; (2) 

 physiological relations, and (3) fungous diseases of plants. The diseases 

 are grouped according to the fungus causing them, under Phycomycetes, 

 Ascomycetes. etc., and special attention is given to the influence of en- 

 vironment on the development of the fungi ; methods of control or of 

 cure are also dwelt on. 



Plant Diseases. — J. B. Parker j describes a disease of Gatalpa leaves 

 due to a fungus, Dklymosphseria Catalpse sp. n. The minute peiithecia 

 grew on pale spots of the leaf, both on the upper and under surfaces. 

 The author compares the effect of the fungus with that of other para- 

 sites on the same leaves. 



W. W. Gilbert $ has examined the root-rot of tobacco plants caused 

 by Thielavia basicola. It induces dwarfing of the plants and finally kills 

 them. The causes that aid the development of the fungus are a soil too 

 rich in humus, excessive moisture, and lack of air in the tobacco beds. 



A description § of shot-hole fungus, Cercospora circumcissa, has been 

 published by the Board of Agriculture. The first indication of the 

 disease is the presence of small pale spots on the leaf, which become 

 yellow ; the fungus itself becomes visible later, tufts of threads with 

 spores at the tips. In time the diseased patches of leaf-tissue drop out, 

 leaving a hole. Peach, almond, cherry, apricot and nectarine are liable 

 to be attacked by the fungus. An account of a useful sulphur spray is 

 also given. It acts as a most efficient fungicide. 



A bad attack of currant black-knot || {Plotrrightia ribesiri) was reported 

 from a garden near Cambridge, and also from Swavesey in the same 

 county. A further case was reported from Middlesex. Most of the 

 trees attacked had died. Corky-scab of potatoes {Spongospora scabies) 

 has appeared in several localities. Other diseases submitted to the Board 

 of Agriculture affected apple-trees (mildew), Douglas Fir seedlings (pro- 

 bably Dothiorella pithya) and periwinkle (Puccinia Vincse). Cucumber 



* Fungous Diseases of Plants. Boston : Guin and Co. (undated) xii. and 240 pp. 

 (240 figs.). See also Bot. Gaz., 1. (1910) pp. 65-7. 



t Ohio Nat., ix. (1909) pp. 509-12 (1 pi.). See also Centralbl. Bakt., xxvii. 

 (1910) p. 272. 



J U.S. Bureau Plant Ind. Bull., No. 158 (1909) 55 pp. (5 pis.). See also Cen- 

 tralbl. Bakt., xxvii. (1910) pp. 272-3. 



§ Journ. Board Agric., xvii. (1910) pp. 211-15. 



!| Tom. cit., pp. 215-17. 



