FSILOTUM. 



495 



The numbers of stages refer to those attached to the 

 figu res. 



The chief difference between this and Isoetes quoad 

 spores, consists in the sporula not being formed in the 

 primarv parent cell, but iu ceils, developed with definite 

 number in those ; there are therefore two sets of forma- 

 tive cells, the first I call the primary parent ; the second, 

 the secondary parent cells. 



There is a tendency to Isoetes in non-uniformity, 

 succeeded by marked uniformity, though not to such a 

 degree. Also, in the remarkable omission of the gru- 

 roous contents of the young spores while enclosed in 

 the second parent cell. 



This is a remarkable instance of the fact, that in 

 Acotyledonous Plants with high foliaceous or axine 

 organs, no analogous sexes occur : nothing like fecunda- 

 tion — nothing like a Pistillum exists. 



Musci Hepatica. — Pisti Inform, evident sexes, ovulum 

 generally removed to a distance during development of 

 fruit (Riccia, and other evaginulate ones perhaps deve- 

 loped into the membrane, enclosing the sporules), form- 

 ing the apex of the seta. Reproductive organs formed 

 at the opposite end long after the changes sequent 

 on fecundation, generally very complex. 



Often radiating dichotomous, often analogous in the 

 female receptacles to those of Fungi. Jungermanniae 

 are analogous to Mosses. 



Azolla. — Pistilliferous, evident traces of fecundation, 

 though the males are not ascertained. Products of the 

 pistilla very different, in only one produced by division, 

 and consequently analogous to sporules. Capsules ana- 

 logous to those of certain Ferns. Habit peculiar, but 

 something like that of Jungermannia. 



Anthoceros. — No pistillum. Traces of fecundation me- 

 diately followed by developement of capsule within the 

 frond, which as it protrudes, carries with it the tissue of 



