270 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



barley that they look like fields of unweeded crops, and where pre- 

 historic man was in consequence not so exclusively a hunter and shep- 

 herd as he has been represented, but learned probably at a very early 

 period to gather and preserve grain. He also considers that the fact 

 that T. diooccum, dicoccoides endures the most extreme climatic con- 

 ditions points to an important economic future for the plant as the 

 possible parent to a race of wheats fit for the needs of many semi-arid 

 regions of all four continents where at present no wheat will grow, and 

 it may so increase materially the world's supply of food.— M. L. H. 



Parasites of Gipsy Moth (II.), Description of Certain Chalci- 



doid. By J. 0. Crawford (U.S.A. Dep. Agr. Bur. Entom., Tech. 

 ser. 19, Part TI. ; April 30, 1910; 16 figs.). — Technical results from 

 the Gipsy Moth Parasite Laboratory. ' The new species described in 

 this paper came from material imported from Japan -and Europe for 

 the purpose of rearing parasites of the gipsy moth and brown tail 

 moth."— F. G. J. 



Parasitic Fungi, Researches on the Life-history of. By 



0. K. Bancroft (Ann. Bot. xxiv. April 1910, pp. 359-371; 1 plate).— 

 In the first of this series of investigations the author gives an account 

 of artificial cultures and infection experiments with Cladosporium her- 

 harum. He shows that the life-cycle is composed of two conidial forms 

 — one a parasitic form, Hormodendron, and the other a saprophytic 

 form, Cladosporium. Each form is capable of giving rise to the other, 

 and the life-cycle appears to be complete without the intervention of an 

 ascigerous stage. The Hormodendron is a summer form which may 

 produce disease on the leaves of several species of plants. When the 

 leaves die the Cladosporium form develops. The plants employed 

 were Brassica oleracea, Cucumis spp. Arctium Lappa, Catalpa hig- 

 nonioides, Althaea, Malva, Oircaeo, Funkia, Phlox, and Digitahs, all 

 of which were readily infected by Hormodendron. Conidia of Clado- 

 sporium, when placed on living leaves, give rise to conidia of Hormo- 

 dendron; direct infection of living leaves by Cladosporium was not 

 obtained. 



In artificial cultures Cladosporium was found to give rise to Hormo- 

 dendron if the temperature was moderately high, but at a lower tem- 

 perature it reproduced itself. In winter Cladosporium exists in the 

 form of microsclerotia, which on the advent of spring germinate and 

 give rise to Cladosporium spores. The latter on germination give rise 

 to conidia of Hormodendron. 



The author shows that C. herharum Link and C. eptphyllum Nees 

 are one and the same plant, and gives a full list of synonomy. 



A. D. C. 



Philadelphus ^Virg-inal.' By G. T. Grignan (Rev. Hort. 

 September 1, 1910, pp. 407-9; two illustrations.)— Depicting young 

 and adult plants of this variety, the latter a large shrub bearing a dense 

 enveloping mass of large rose-like double white flowers. Eaised by 



