806 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



nutritive gelatine. In some cases pieces of bark or wood from Oak or 

 Pine were added ; in other cases the spores in water were placed near, but 

 not in contact with, pieces of Oak or Pine ; the effects of ether vapour 

 were also tried. Eipe ascospores, which germinated slowly in pure water, 

 gave better results when in contact with, or exposed to the exhalations 

 from, the pieces of Oak or Pine, which appear to cause a chemical stimulus. 

 Ether vapour also promoted germination. The experiments indicate that, 

 in nature, the ascospores left dry soon lose the power of germination, but 

 this can be again stimulated by their coming in contact with pieces of 

 bark or wood. If the stimulus is only slight, conidia are most abundantly 

 produced ; if stimulus is stronger, germ-tubes are formed more abundantly. 



W. G. S. 



Fungi, Study of parasitic, in the United States. By Dr. G. P. 



Clinton (Bull. Bot. Dep. Trin. xliii. p. 87, July 1904). — An address treat- 

 ing the subject from an historical view, divided into three periods : of 

 collection, 1812-70 ; instruction, dating from the establishment of a 

 department of cryptogamic botany at Harvard University in 1870 ; 

 and investigation, from the founding of experiment stations in 1887. 

 The names of those who have been engaged in the work are given, and 

 a brief outline of their subjects. — E. A. B. 



Gall, Crown. By Wendell Paddock ( U.S.A. Agr. Exp. Stn. Colorado, 

 Bull. 86, Dec. 1903 ; 3 plates). — This bulletin is devoted to the so-called 

 crown galls, which are irregular outgrowths of tissue that commonly form 

 around the crown of a tree, just below the surface of the ground. 



It is found on a variety of plants, including Almond, Apple, Apricot, 

 Blackberry, Cherry, Chestnut, English Walnut, Grape, Peach, Pear, Plum, 

 Poplar, and Raspberry. It has been found that the disease can be transferred 

 readily from the Almond to Peach and Apricot trees. Serious investiga- 

 tion of the galls on other trees and plants has not yet been undertaken, 

 but it is likely that the disease is of the same nature, if not induced by the 

 same organism. 



The disease does not appear to be so destructive to older trees as to 

 nursery stock ; some experiments indicate that in such cases the disease 

 may be held in check in a measure. The mode of treatment consists in 

 examining the trees every season and cutting away all traces of galls from 

 about the crowns. The wounds then to be thoroughly covered with a 

 wound paste. All diseased wood should be collected and burnt. The 

 important point is to keep the disease out of the orchards, and secure 

 nursery stock free from infection. — M. C. C. 



Garrya, Notes on, with descriptions of New Species. By 



A. Eastwood (Bot. Gaz. xxxvi. No. 6, p. 456). — This includes five new 

 species and one variety. — G. H. 



Gentiana acaulis. By S. Mottet (Rev. Hort. pp. 34-35, Jan. 16, 

 1904 ; 1 woodcut of G. scabra). — It is incidentally remarked that humus 

 (leaf-mould) is fatal to G. acaulis, and it should be planted in stiff clayey 

 soil, unsophisticated in any way, opposite treatment explaining many 

 failures in careful hands. — C. T. D. 



