XIV LYCOPODINE^E 467 



to be always wanting, as is usually the case in Eqiiisetum, and 

 a- definite layer of cells surrounding the venter is also not 

 usually evident. L. pJilegmaria is especially noteworthy on 

 account of the large number of canal cells, which range in 

 number from three to five. Treub also states that the nucleus 

 of each canal cell may divide again, so that in regard to the 

 number of canal cells L. pJilegmaria, of all Pteridophytes, 

 approaches most closely to the Bryophytes. Another peculi- 

 arity of this species is the presence of numerous paraphyses 

 among the sexual organs, in which respect it also offers an 

 analogy with many Bryophytes. 



TJie Embryo ^ 



Treub has traced the development of the embryo in L. 

 pJilegmaria through all its stages, and has shown that L. 

 cernuuin corresponds closely to it, and Goebel's " investigations 

 upon L. inundattun show that this species does not differ 

 essentially from the others. The first division in the embryo 

 is transverse, and of the two primary cells the one next the 

 archegonium remains undivided, or divides once by a transverse 

 wall and forms the suspensor, which is characteristic of all 

 investigated Lycopodineae, while the lower cell alone gives rise 

 to the embryo proper. In the embryonal cell the first wall is 

 a somewhat oblique transverse one, which divides it into unequal 

 cells. In the larger of these a wall forms at right angles to the 

 primary wall (Fig. 245, A), and this is soon followed in the 

 smaller cell by a similar one, so that the embryo is divided into 

 quadrants. Of these the two lower form the foot, while of the 

 upper ones in L. pJilegmaria, the one formed from the larger 

 of the two primary cells {moitie convexe of Treub) produces the 

 cotyledon, the other the stem apex. The primary root, w^hich 

 in Lycopodium arises very late, originates from the same quad- 

 rant as the cotyledon. 



In Z. cernuum, while the early divisions correspond exactly 

 with those of L. pJdegmaria, the further development of the 

 embryo shows some noteworthy differences. i\s in that 

 species, the two lower quadrants form the foot, which here 

 remains completely buried within the prothallium. From the 

 upper part of the embryo is next developed what Treub calls 



1 Treub (2). "- Goebel (18). 



