BOOKS AND CURRENT LITERATURE 



Morphology of Blastocladia. — The true systematic position of tlie 

 genus Blastocladia, a phycomycetous fungus, is established, by Barrett,^ 

 as the result of an excellent critical investigation. His paper is accom- 

 panied by convincing illustrations of its morphology and development. 

 This study of a new species, B. strangidata, not only confirms but adds 

 basis for support to the opinion of Schroeter that the genus should be 

 included in the Leptomitaceae. The fungus, B. strangulatn , consists of 

 a cyhndrical basal cell, attached to the substratum by rhizoids and 

 supporting above a dichotomously or umbellatelj' branched .system of 

 hypae which terminate in reproductive bodies, either zoo.sporangia or 

 resting sporangia. The mycelium is more or less markedly constricted 

 at the points of origin of the branches. Pseudo-septa, quite unlike 

 anything previously described, occur at the points of constriction. 

 These pseudo-septa originate as separate protrusions, from the wall and 

 increase in length, probably by accretion, until they fuse at the center 

 of the cell. Their chemical nature is not definiteh' established. The 

 zoosporangia, broadly oval to spherical in form, originate terminally or 

 subterminally, and remain attached, often in chains, long after the 

 zoospores have been discharged. Segmentation in the delimitation of 

 zoospores begins at the periphery of the sporangium and the resultant 

 zoospores are typically uninucleate and uniciliate although quite fre- 

 quently there are those with two nuclei and two cilia and in rare cases 

 a triciliate condition was observed. On germination the cilia are re- 

 tracted and the body of the zoospore becomes the basal cell of the new 

 plant. The zoosporangia are provided with papillae of dehiscence. The 

 structure and behavior of these papillae in the expulsion of the zoospores 

 appear to be entirely unique. The resting sporangia, which are decidu- 

 ous when mature, originate in the same manner, in general, as the 

 zoosporangia and can be distinguished from them by the thicker walls 

 and the absence of papillae. The wall, consisting of three layers, an 

 outer and inner, smooth and hyaline, and a middle, thick perforated 

 and orange colored, begins to thicken early in the development of the 



1 Barrett, J. T., The Development of Blastocladia strangulala n. sp. Bot. G;iz. 

 54 : 353-371, pis. 28-30. 1912. 



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