292 SUMMARY OF CURRENT RESEARCHES RELATING TO 



much more numerous than those of B, obliquum, which again are far 

 more numerous than those of B. dissectnm. The distinguishing characters 

 of B. dissectnm and B. ohUquimi are indicated, the most suggestive 

 difference being, in the fertile spike, where in B. dissectum a large 

 number of abortive sporangia occur: Examination shows that B. dissec- 

 tum is partially, or probably, entirely sterile ; and the conclusion is 

 reached that this plant is a sterile mutant from B. obliquiwi. It never 

 occurs save in association with B. obliquum, and there is no evidence 

 that it reproduces itself. • A. G. 



Gametophyte and Embryo of Botrychium obliquum Mtihl. — 

 D.H.Campbell {Anmds of Botany, 1921, 35, 141-58). The summary 

 of this paper runs as follows: — 1. The gametophyte and sexual organs 

 of Botrychium ohliquum do not differ essentially from those of other 

 species. 2. The embryo differs in several important particulars from 

 both B. Lunaria and B. virginianum, resembling the latter in having 

 the cotyledon well developed, but differing in the endogenous origin 

 of the root, in the bipolar arrangement of cotyledon and root, and 

 especially in the presence of a suspensor. The embryo is much more 

 like that of some species of Ophioglossum and Dansea than it is like 

 other species of Botrychium. ?>. The stem apex grows from a single 

 apical cell, which is much like that of Ophioglossom vidyatum. The 

 young cotyledon also has a single apical cell. 4. There is a single 

 primary vascular strand which extends without interruption from the 

 cotyledon into the root. There is no cauline stele, and the primary 

 vascular strand is augmented later by additions from the traces of the 

 second and third leaves. 5. The cotyledon has a ternate lamina with 

 dichotomous venation. The bundle of the petiole is collateral in 

 structure. 6. The root early develops a conspicuous tetrahedral apical 

 cell, and its development is much like that of the later roots. The 

 bundle is usually diarch, but may be monarch. 



B. lunaria, B. obliquum and B. virginianum represent three types 

 of adult sporophyte which differ in a number of particulars — viz. form, 

 texture, and venation of the leaf ; size of sporangium ; position of 

 sporaugiophore ; character of leaf -base. The author believes ^. virgini- 

 anum to differ from other species sufficiently to justify the raising of 

 the sub-genus Osmundopteris to generic rank, and would restrict the 

 name Botrychium to B. lunaria and its near allies ; whereas, should 

 the other species of the Ternatum group agree with B. ohliquum in the 

 structure of the embryo, there would be ample reason for accepting 

 Lyon's genus tSceptridium. A. Gr. 



Missing Link in Osmundites, — M. C. Stopes {Annals of Botany, 

 1921, 35, 55-61, 1 pi. and lig.). A description and discussion of a 

 waterworn fossil specimen of Osmundites from AVollumbilla Creek, 

 Queensland, described as probably cretaceous, and now preserved partly 

 in the British Museum (ISI'atural History) and partly in the National 

 Museum at Melbonrne. It represents a portion of a rhizome with the 

 surrounding leaf-bases, and is remarkable in possessing a solid stele and 

 normal, simple Osmundaceous meristeles in the leaf-bases. It is of 



