260 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



23. Summer fallowing should be practised on dry farms, first, to 

 store the precipitation of two or more years for the use of one crop, 

 and secondly, to set free an abundance of plant food which will enable 

 crops to mature with less water. 



The total dry matter referred to in these experiments refers to the 

 part of the plant above ground, excepting in the case of the sugar-beets 

 in which the roots and leaves were weighed together. — M. L. H. 



Irrig-ation in N. Dakota. By T. E. Atkinson {U.S.A. Dep. 

 Agr., Off. Exp. Stn., Bull. 219; September 1910; maps). — A short 

 account of the general features and irrigation possibilities of N. Dakota, 

 a history of recent legislation on the subject, and a list of the various 

 irrigation schemes which have been or are in process of being carried 

 out throughout the State. — M. L. H. 



Jacobinia suberecta {Bot. Mag. tab. 8350). — Nat. ord. Acan- 



tJiaceae; tribe Justicaeae. Urugnay. Herb, leaves 2^ inches long; 

 cymes peduncled, 5-10 flowered ; corolla 2-lipped, bright scarlet, 

 1^ inches long. — G. H. 



Juncaceae, Parasitic Root Diseases of. By E. J. Schwartz 



{Ann. Bot. vol. xxiv. July 1910, pp. 511-521). — The roots of Juncus 

 Bufonius, J. articulatus, and J. lamprocarpus are found to be subject 

 to attacks of two distinct parasites — viz. the fungus Entorhiza cyperi- 

 cola and the Myxomycete Sorosphaera Junci. 



The life-history of S. Junci is dealt with in detail. It usually gains 

 entrance to the plant by the root hairs, though direct infection through 

 the cells of the young root is also probable; it is first noticeable as an 

 amoeba-like body. The outer cells only of the root are infected, and 

 there is no hypertrophy as in the case of aS'. V eronicae or Plasviodio- 

 phora. The amoebae increase in size, but do not coalesce to form 

 Plasmodia. Ultimately they give rise to a mass of spores. 



In the case of Entorhiza the roots infected form small tubercles, 

 the cells of the cortex being occupied with the fungus. Infection 

 appears to take place by means of the entry of conidia into the root 

 hairs. The mycelium penetrates the root and gives rise to masses of 

 dark spores in the cortical layers. Entorhiza is probably allied to the 

 Ustilagineae. — A. D. G. 



Leaf poller, The oblique-banded. By E. Dwight Sanderson and 

 A. D. Jackson {Jour. Econ. Etoni. vol. ii. pt. 6, pp. 391-403; 

 December 1909; plates). — The larvae of this tortrix moth {Archips 

 rosoceana Harris) occasionally cause severe damage to roses and a bad 

 case is here reported and many new details concerning its life history are 

 given. The pest had been imported into the New Hampshire nursery 

 on ' Killarney ' roses from Ohio, and had spread rapidly through the 

 house. When the attack is mild the lower leaves only are damaged 

 but where it is severe the terminal leaves are rolled together and the 

 larva burrows into the bud thus checking growth and destroying flowers. 



