Journal of Applied Microscopy. 343 



CURRENT BOTANICAL LITERATURE. 



Charles J. Chamberlain. 



Books for review and separates of papers on botanical subjects should be sent to 



Charles J. Chamberlain, University of Chicago, 



Chicago, 111. 



REVIEWS. 



..,,,. T^ . , The fun<>i belongine' to the Hemiasci 



Popta, Canna M. L. Beitrag zur Kentniss der '^ o o 



Hemiasci. Flora. 86: 1-46. pi. i and 2, have been variously classified. De 



'^99- Bary (1S()5) placed J^rotomyccs with 



the Ascomycetes as their simplest form, but later concluded that it belonged to 



the Ustilagineae. Schroter united Frotoinyces with Endogene into an independent 



order, Protomycetes, following the Zygomycetes and Oomycetes. In Raben- 



horst's Kryptogamen Flora, Theloboliis, now usually classed with the Hemiasci, 



is placed under the Pezizaceae. Brefeld includes in the Hemiasci three genera, 



Ascoidea, Froto7nyces, and T/ie/obolus, and places the group between the Phyco- 



mycetes and the Ascomycetes. This position is given because the sporangia agree 



more nearly with those of Phycomycetes than with the asci of Ascomycetes, 



while the \-egetative characters show more resemblance to those of Ascomycetes. 



The present work was undertaken in the hope that a study of the development of 



the sporangia and spore formation might shed some light upon the subject. 



Ascoiaea I'ubesceJis Brefeld and Lindau, Protoniyces hellidis Krieger and Frotomyces 



macrosporus Unger were studied in detail. A chapter is devoted to a comparison 



of the sporangium development of the Hemiasci with that of the Ascomycetes 



and Phycomycetes. The conclusion is that in their spore development the 



Hemiasci do not constitute a single group, but rather that a part (Ascoidea) 



shows more analog}^ to the Ascomycetes, while others (Protoniyces) are nearer 



the Phycomycetes. c. j. c. 



The number of chromosomes in Naias 

 Guignard, L. Sur la formation du pollen et la . . i • 1 1 ^ j 



reduction chromatique dan le Naias major. '>''VOr IS twelve m the sporophyte and 

 Comptes rendus des seances de I'Acad. des six in the gametophyte, the lowest 

 ^' ^ number yet reported in any flowering 



plant. This paper deals with the two mitotic divisions by which the four pollen 

 grains are formed from the pollen mother cell. In the prophase of the first 

 division the spirem splits longitudinally and segments into six primary chromo- 

 somes, each of which consists of two pieces. Each of these pieces during 

 the succeeding contraction and growth shows a double row of granules, a prepa- 

 ration for a second splitting, so that the primary chromosome is to be considered 

 quadruple. As the primary chromosome separates into its two parts (secondary 

 chromosomes), the splitting already presaged by the division of the granules 

 begins to take place, but is not entirely completed since the two pieces remain 

 united at their extremities, thus forming a V with its apex in contact with the 

 spindle threads. Each of the daughter nuclei receives six double (secondary) 

 chromosomes. In the second division six V-shaped chromosomes appear. At 

 the point of the V there is an interruption in the linin support, and everything 



