PROCEEDINGS OF THE CANADIAN INSTITUTE. 



The Gametophyte of Botrychium Virginianum. By Edward C. Jeffrey, 

 B.A., Lecturer in Biology University of Toronto. 



(Read November 21, 1896.) 



A complete description of the gametophyte of the Ophioglossaceae has long been 

 a desideratum. 



Since the discovery by Mettenius, in 1856, of the subterranean prothallium of 

 Ophioglossum pedunculosum, and by Hofmeister, in 1857, of that of Botrychium 

 lunaria, nothing has been added till recently to their necessarily incomplete 

 accounts of the gametophyte in these species. Our latest knowledge on this subject 

 is derived from a brief description of incomplete material of the prothallium of 

 Botrychium virginianum found in 1893 ^t Grosse Isle, Michigan, by Professor 

 Douglas Campbell, which was published in the proceedings of the Oxford meeting 

 of the British Association in 1894. 



During the summer of 1895 the writer secured a large number of prothallia of 

 the same species at Little Metis in the Province of Quebec. On examination it was 

 found that the material thus obtained afforded a complete elucidation of the 

 development and structure of the antheridia and archegonia, and a less satisfactory 

 series of stages in the segmentation of the embryo. Last summer the remaining 

 prothallia were removed to the number of about six hundred, and, although they 

 have only been partially studied yet, owing to technical difficulties in embedding 

 them, those examined have supplied all the lacking stages of the development of the 

 young sporophyte. 



It is proposed at the present time to furnish a brief account of the features of 

 interest — a fuller description will shortly appear in the Transactions of the Canadian 

 Institute. 



All the younger prothallia were found in a single circular depression of 

 sphagnum moss about ten feet in diameter, near a corduroy road, running through 

 the wooded margin of a peat and huckleberry swamp at Little Metis, P.Q. Older 

 prothallia were abundant with those bearing fertilized and unfertilized archegonia 

 and younger embryos. 



I have also found young sporophytes of several years' growth in the woods on 

 the heights back of Metis; in the " Flats" below the "Whirlpool" on the Niagara 

 river, and also in rich woods along the valley of the Don, near Toronto. In all 

 the examples last referred to the young spore plant was still attached to the 

 gametophyte. It seems probable that the prothallia of our common Canadian 

 species of Botrychium are much commoner than has been hitherto supposed. It 

 is necessary to add, however, that although my attention has been directed to the 

 subject for some three years past, I have not yet succeeded in finding the younger 

 stages of the prothallia in any other spot than the sphagnum basin in the swamp 

 at Little Metis. 



The gametophyte of Botrychium virginianum is of flattened oval shape, the 

 narrower end of the prothallium being terminated by the growing point. My 

 examples are from two to eighteen millimetres in length, by one and a-half to eight 

 millimetres in breadth. Their thickness increases from the growing end backwards. 

 The sides and lower surface of the prothallium are covered in younger specimens 

 with multicellular hairs. In older plants these tend to disappear. The middle of 

 the upper surface is occupied by a well-defined ridge, upon which the antheridia 



