1908] CURRENT LITERATURE 6r 



initials, and determine morphological relationships merely by "how things look 

 in the mature condition." 



SER^^T extends Velenovsky's "angular leaf" idea from pteridophytes to 

 brj'ophytes, and describes such a leaf in Mastigobrj-um, where it is easily dis- 

 tinguished by its transverse insertion as well as by its form. It is situated at the 

 base of two branches and he considers it as formed by the concrescence of Che 

 first leaf of both. This angular leaf, he says, Is present in ail liverworts whose 

 branches arise from the half-segment; but it is elsewhere not so typical (this 

 sounds Goethean) as in Mastigobr)^um. It is lacking in those whose branches 

 arise only from the basiscopic part of the half-segment. 



In intercalary branching both of liverworts and mosses the branch is endoge- 

 nous and breaks through a sheath, which may be split into segments that Servit 

 calls Bldftchen, He has confirmed in all cases Velenovsky's "law" (tliat the 

 branches in mosses arise without exception in the axil of the leaf below them!) by 

 esamining "extraordinarily abundant material;" but he does not say that in any 

 case he has determined the relation of the branch initial to the leaf initial. Until 

 that is done the current view, which rests upon careful studies of Leitgeb, will 

 prevail. 



BucH has made a thorough study of the two modes of vegetative propagation 

 of Blasia pusilla,^^ especially of the development and germination of the gemmae 

 produced in the flasklike receptacles. These arise both on male and female plants, 

 but are rare on the latter if they form embr)-os. While the brood-buds (modified 

 tips) are the chief means of propagation in summer, the gemmae probably do nc^ 

 germinate in the summer and certainly not in the autumn, but hibernate and start 

 new^ plants in the spring. Shoots arise from either side (seldom both), where there 

 is a zone of four small cells. One of the upper two produces a thallus initial by 

 three successive di\-isions of the protruded tube, while the two lower ones produce 

 rhizoids.— C. R. B. 



Mutations of Oenothera.— MacDoug.^l^* and his collaborators have published 

 a further account of evolutionar>- studies upon the Oenotheras. Taxonomk 

 descriptions of se\'eral of the mutants from O. Lamarckiana, as they grew in the 

 New York Botanical Garden, are given, including O. alMda, O. oblonga, O. 

 scmtiUans, O. hrevistylls, and O. UUa. These wiU be valuable for comparison 

 with cultures elsewhere. The English "O. biennis^' as growing in the vicinity of - 

 Liverpool, has been found to be O. Lamarckiana, and gro^^-ing wild with it are two 

 of the mutants, O. rubrinervis and O. lata, the latter maturing ponen, contrary to 

 its habit elsewhere. The cultures of O. Lamarckiann from DeVioes' seeds gave 

 ciV nf tK^ rr...i-nr.^. A^rr^Y^i^ hv that aiithor and also nine other types which could 



and relationships of the Oenothera; 

 no. 8r. DP. 02. i*ls. 22. iiss. 7?. 1907 



jrmehrung von Blasia pusUla (Mich) 



pp, 42. pis. 2. figs. 7. 1907- 



iHinx, G. H., Mut^KHis, variatiors 



f^ Institution of Wa^ington, Pub! 



