REPRODUCTIVE ORGANS. 



449 



hope to extend our views. Some there are indeed who, while the 

 whole course of their studies has been to neglect structure, deny the 

 applicability of presumptive evidence in favour of doctrines, the sub- 

 jects of which are barely susceptible of direct proof. Thus Greville 

 and Arnott, angrily ask, what do persons mean by saying that mosses 

 have pistilla, etc. ? they protest against such community of applica- 

 tion in the use of terms. Many more deny sexuality because it has 

 not been proved. Considering the invisible nature of the fluid of the 

 anthers of mosses, etc. how do they expect that we are to demon- 

 strate its application to the pistil, and the subsequent steps ? As well 

 might they doubt the necessity of the application of the boyau to an 

 ovule, (or the existence of the boyau itself,) because the derivation 

 of the embryo cannot be proved. 



One word more ; in all cases the appearance of the reproductive 

 body after impregnation, is of late date ; that date becomes later as 

 we descend the scale. The embryonary sac of Phsenogams does not 

 always exist at the time of application of the boyau, and the appear- 

 ance of the embryo is always posterior to this. 



Again, ferns are superior to mosses in this, that in many cases the 

 male influence is exerted directly on the parts that become the thecse, 

 which is not the case in mosses. 



18th. — Continued examining ferns, and to-day completes my know- 

 ledge of the ramenta of three different genera. 



In the first which is Cryptogamma, the resemblance of the young 

 ramenta to the anthers of Jungermannia is evident enough, they 

 are capital, and the head is at one period filled with granular 

 matter : so are the cells throughout, to a greater or less extent. 

 They are to be seen in all stages of development on the pinna? of a 

 very young frond, those near its base having perhaps effected their 

 purpose, while those at the apex of the pinna, or the prolonging 

 part of pinnula, may be formed of only one cell. It is curious that 

 the terminal cell does not become spherical for some time : in its 

 earlier stages it is cylindrical like the rest. 



The appearances of the old ones are, if possible, more markedly in 

 favour of my hypothesis; there is the same aggregation of grumous 

 congealed matter about the ends of each cell, the same curious com- 

 munication between these masses which hide the septa from view, 

 evincing a greater or less tendency to assume the peculiar fuscesent 

 or fusco-brown appearance. I observed in two instances what ap- 

 peared to me decided irregular openings in the terminal cell, from 



3 m 



