1896-97.] THE GAMETOPHVTE OF BOTRYCHUM VIRGINIANUM. 27I 



younger anterior region of the prothallus. Figure 4 is of a lobed game- 

 tophyte ; figure 6 shows a similar condition in which two embryos, 

 evi. I, em. 2, are to be seen. The depression of the antheridial ridge in 

 the posterior region by marginal growth is particularly well-marked. 

 These lobed forms are quite abundant among the Metis specimens, but 

 the Toronto plants did not manifest this peculiarity. I am inclined to 

 believe that the conditions of life in the two cases may have been the 

 cause of this difference. The Metis specimens were found in wet, peaty 

 soil. The Toronto plants, on the contrary, grew in rich, yet rather dry, 

 forest mould. Older lobed prothallia have almost invariably two 

 sporophytes attached to them. In figure 7, is represented an example 

 in which the first root of the young sporophyte has reached a consider- 

 able size. At this stage the axis of the young sporophyte, which, in 

 earlier phases, is nearly always at right angles to that of the prothallus, 

 becomes often more or less oblique, as in the example figured. This 

 rotation of the axis is probably due to the continued growth of the 

 prothallium after the formation of the embryo. Figure 8 shows a 

 prothallium in which two roots of the attached sporophyte have grown 

 to a considerable length, although the cotyledon is short and still 

 unfolded. In figure 9, we have a small gametophyte with only one 

 root, and yet having the cotyledon fully expanded. The first leaf may 

 expand either after one, two, or three roots have been formed, according 

 to the vigor of the plant, and may always be recognized by its seeming 

 to grow out of the proximal end of the first and stoutest root. Figure 

 10, is of a strong plant with three precotyledonary roots. The lamina 

 of the cotyledon is not bilaterally symmetrical, as in most of the 

 FilicinecB, but of the palmate type represented by Ophioglossuvi pedun- 

 culosum. As may be seen from figures 9 and 10, the first leaf varies 

 considerably in complexity in accordance with the greater or less 

 robustness of the plant from which it originates. In the next drawing, 

 figure II, is represented a lobed prothallium, on which are two older 

 sporeplants, deprived of the leaves of the year of their collection. 

 Figure 12 shows a Toronto specimen, bearing two well-advanced 

 sporophytes. Figure 13 is a representation of a bifurcated sporeplant, 

 two examples of which have been found. Figure 14 is interesting, for 

 it represents a sporophyte which has already developed the fertile 

 ventral segment, and is yet still attached to the mother prothallium. 

 The sporeplant in this case is eight years old, as indicated by the 

 number of foliar lacuna; in the fibro-vascular cylinder. There seems to 

 be little danger of error in drawing this inference, for a considerable 

 acquaintance with the young sporophyte enables me to state positively, 

 that never more than one leaf is developed at a time, and in all 



