INTRODUCTION TO CEYPTOGAMIC BOTANY. 



27 



value ; but the student will learn as much, perhaps, from the 

 observance of their differences, as if they were in every respect 

 perfectly accordant 



16. There is another point which makes the study of 

 cryptogamic botany peculiarly interesting, viz.: — because so 

 large a portion of fossil vegetation is so intimately related to 

 some of the nobler Cryptogams, and possibly exhibits far 

 grander and more highly organised individuals than any 

 which at the present sera occiu: in a Hving state. It is for- 

 tunate that these, in some cases, still retain their Spores in such 

 a perfect condition, as to admit of accurate appreciation. In 

 some fossil fruits,* indeed, which have certain primd facie 



Fig. 12. 



a. b. c. Eggs of Aplysia depilans from Vanbeneden Recherches sur le 

 dSvelopement des Aplysies, in Ann. d. Sc. Nat., ser. ii. vol. 

 15, p. 123. 

 a. Contained in thread, natural size.t 

 h. Thread and eggs magnified, showing thequadricellular vitellus. 



c. Vitellus in different stages, highly magnified. 



d. e. Oloionema paradoxan, Kg., being in fact the eggs of some Tipula. 



d. Thread, with its rows of eggs magnified. 



e. Eggs highly magnified. See Berk, in Ann. of Nat. Hist., vol. 7, 



p. 449. 



* Carpolithes OvvZum, Brongn. and Folliculites minutulus, Bronn, 

 Hook. fil. in proceedings of Geological Society, 1855, p. 562, 566. 

 t This is, I believe, Ulva defracta, Eng. Bot. 



