NOTES ON RECENT RESEARCH. 



503 



system of well-differentiated type, with tracheid and sieve-tube com- 

 ponents, or, in the case of certain Pteridophytes, can clearly be shown to 

 have lost it by degeneration. The Bryophyta have no such system. But 

 the exigencies of increasing bulk and erect habit have led to the acquire- 

 ment of a conducting system, simple in most cases, but attaining high 

 complexity, as in the Polytrichacece. The study of this conducting 

 system in Liverworts and Mosses forms the subject of this considerable 

 paper. — B. I. L. 



Bulgaria polymorpha. 



Bulgraria polymorpha, Biologry of. By R. H. Biffen, B.A. 

 [Ann. Bot. vol. xv. No. Ivii. p. 119). — This paper deals with the develop- 

 ment of the fungus under artificial culture. A chief object of the author 

 was to observe the effect of its action on wood. As a rule it is a 

 saprophyte, but is capable of becoming parasitic, and Ludwig even con- 

 siders it a dangerous parasite on the Oak. Mr. Bift'en says that the 

 results of the action of Bulgaria ijolymorplia upon Oak-wood are to 

 dissolve and probably decompose the lignin, and to dissolve the pectates 

 of the middle lamella, but he adds that the action is too slight, in the 

 cases he has examined, to warrant the supposition that the fungus is 

 capable of causing a really serious tree disease. — B. I. L. 



Chromosomes. 



Chromosomes in Larix leptolepis, Gord., Reduction of. By 



Prof. Dr. C. Ishikawa (Tokyo) (Bcih. Bot. Cent, bd. 11, ht. 1, p 6).— 

 Twelve chromosomes were found in the pollen-grains, and each divides 

 into two. These, after travelling to the poles, unite, forming twelve ring- 

 shaped chromosomes. These become gradually disintegrated ; their 

 elements again become built up into twelve chromosomes, which behave 

 in a similar manner. — G. F. S.-E. 



Cladophora. 



Cladophora. " Ueber einige Verhaltnisse des Baues und Wachsthums 

 von Cladophora." By Brand {Bcih. Bot. Cent. bd. x. ht. 8, pp. 481-521, 

 with ten figures). — This is a continuation of the author's researches on 

 the cell-wall and mode of growth, chlorophores and nucleus of the above 

 Alga. The author describes an outer layer or " decklamella " of the cell- 

 wall which can be rendered distinct by acetic acid and other reagents ; it 

 is outside the ordinary inner and outer layers. A description is also given 

 of the manner in which the transverse septa become divided into two 

 layers, and of the way in which the intercellular spaces are formed at the 

 corners. The formation of the side branches by outgrowths appearing 

 below the septa is traced in detail, and the resulting apparent dichotomy 

 is explained. The chlorophores are generally reticulated, though small 

 isolated plates and large pitted plates also occur. Many nuclei are fre- 

 quently present in one cell, though their number is often reduced to 

 two or even one. The growth of the cell-wall here described is of 

 importance, and the paper should be of interest to algologists as explaining 

 obscure points in the alg£E generally. — G. F. S.-E. 



