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and general life-habits. A limited number of botanists have confined their 

 studies, or at least have devoted much time, to the investigation of the micro- 

 scopic internal structure of these plants (anatomy), the more minute structure 

 of the cells themselves (cytology), or the study of the embryo (embryology). A 

 recent contribution by Allen ^ in the American Journal of Botany relates to the 

 four-lobed form taken by the cells in the capsule of Catharinaea. It will be 

 recalled by our readers that the cells in the capsules of the mosses and hepatics 

 which give rise directly to spores are termed "spore mother cells," and that such 

 cells always normally give rise to four spores often termed tetraspores. The 

 formation of tetraspores has been for a long time a subject of great interest in 

 that certain structures in the nucleus of the cells of the capsule, and indeed of 

 the whole sporophyte, known as chromosomes, are twice as many in each nucleus 

 as in the nuclei of the gametophyte. The number of these chromosomes is 

 doubled whenever the egg-cell is fertilized by the sperm and the number is not 

 again reduced until the four tetraspores are formed in the spore mother cells of 

 the capsule. This division of the material in the spore mother cells to form 

 tetraspores is for this reason known as the "reduction division." 



Allen reports that from living immature capsules of Catharinaea collected 

 in southern Wisconsin in August, 19 15, he pressed out the spore mother cells and 

 found them to be strongly four-lobed. This lobing is, as he notes, almost uni- 

 versal in the Jungermanniales but further notes: "That is, I think, the first 

 observed case of the occurrence of four-lobed spore mother cells in a bryophyte 

 not a member of the Jungermanniales. It remains to be seen to what extent 

 this character appears among the Bryales." Here is a good chance for our 

 readers to contribute something new to science. When you find nearly mature 

 capsules press out the contents and examine under the microscope, then record 

 carefully the results and contribute your notes to the Bryologist. 



Another interesting point noted by Allen was that there is a plastid in each 

 lobe of the spore mother cell and that the early division of a single plastid into 

 four has been known for some time to occur in Anthoceros,^ and also, to judge 

 from the work of Sapehin^ and Melin,^ it is of common occurrence among the 

 Musci. 



Allen reports that "There are rather striking differences in size between the 

 spore mother cells of plants collected in different localities, although the mother 

 cells borne in a single capsule differ little in size, and, so far as my observations 

 have gone, there is no great variation in this respect as between different plants 

 growing in the same clump. Along with these differences in size of the spore 

 mother cells between plants of different localities go other well-marked differ- 

 ences in such characters as size of plant, size of leaf, number of lamellae on the 



1 Allen, Charles E. Four-lobed Spore Mother Cells in Catharinea. Amer. Journ. Botany 3 : 

 456-460. Oct., 19 16. 



^ Davis, B. M. The Spore-mother-cell of Anthoceros. Bot. Gaz. 28: 89-109. 1899. 



3 Sapehin, A. A. Ueber das Verhalten der Plastiden im sporogenen Gewebe. Bericht. Deiitsch 

 Bot. Ges. 39: 491-496. 1911. 



* Melin, E. Die Sporogenese von Sphagnum squarrosum Pers. Nebst einigen Bemerkungen 

 iiber das Antheridium von Sphagnum actitifulium Ehrh. Svensk Bot. Tidsk. 9: 261-293. iQiS- 



