16 



THE OPHIOGLOSSALES 



THE GAMETOPHYTE OF BOTRYCHIUM. 



Hofmeister (Hofmeister 1), in his studies of the Archegoniates, has included 

 Botrychium lunaria, whose prothalHum he discovered in 1854. No further contri- 

 butions to our knowledge of the subject are recorded until 1893, when the writer dis- 

 covered at Grosse He, Michigan, a number of old prothallia oiB. virginianum, with 

 the young sporophytes attached. The earliest germination stages of this species 

 were also secured. In 1895, Prof E. C. Jeffrey collected at several points in Canada 

 a large number of prothallia of this species, and his account (Jeffrey I) is much the 

 most satisfactory one which had appeared up to that time. In the spring of 1903 

 Lyon (Lyon 1) discovered prothallia of 5. obliquum in Minnesota, and the following 

 year secured a few specimens of B. simplex and B. matricariafolium, but he has only 

 published a brief note in regard to these species. He states that the reproductive 

 organs in B. obliquum "differ essentially from those of 5. virginianum," but he does 

 not explain in what these differences consist. Bruchmann, who has added so much 

 to our knowledge of the gametophyte of the European Lycopodiaceae and Ophio- 

 glossaceae, has recently given a very satisfactory account of the prothalHum and 

 embryo of B. lunaria, which he found in various parts of Germany and Switzerland. 

 He corrected certain errors made by Hofmeister in his account of the same species. 

 (Bruchmann 2.) 



Fig. 6. — Botrychium virginianum. 



A, B. Germinating spore (B, optical section). 



C. Three gametoph3rtes, X3; em, embryo. 



D. Section of gametophyte, X12; the shaded region is that occupied by the endophyte. S antheridia. 



E. Apical region of gametophyte, X150. 



F. Short multicellular hair or paraphysis. 



Owing to the kindness of Professor Jeffrey, a large number of prothallia and 

 young sporophytes of 5. virginianum, together with several slides showing the sexual 

 organs and embryos, were put at my disposal. This has made it possible for me to 

 make a very satisfactory study of the reproductive organs and embryo in this species. 



The spores of Botrychium, like those of Ophioglossum, are of the tetrahedral 

 type and are quite colorless, their contents showing the usual granular appearance, 

 but without any trace of chlorophyll. The early stages of germination are exactly 

 like those of Ophioglossum, the first division wall being transverse, this being then 

 followed by a second wall in the inner cell at right angles to the primary wall (fig. 6, 

 A, B). A few chloroplasts were seen in some of the cells, but this does not seem to 

 be a constant character and perhaps was an abnormality due to the spores having 



