AcHOGF.Nb.] I 11. n ILES 



and their naked ovul apon the margin ■ I 



I '( rnaare apon the \t I tsmnnda. I 



. through Sahsburia, whose leavet migbl 

 The affinity of Feme with Equisetum, 



.iinuhir vessels, than in ai 

 known bj their axillary sport 

 rerj different, that it is difficult to find poin 

 ime of tli 

 The organ in Ferns which di 

 ease i ] < U c mtains the reproductive nutter, Bj man) h 

 kind of pericarp tially connected with the power of conv< . 



the male apparatus to the "\ ales, and implies tb 

 betwet n the various parts that it contains, nothing of which kind . 



Ferns, it is not necessary to insist apon the impropriety of applj 

 i \ as it is to show that the spoil 



demonstrate with whal or modifications of organs it reall) '. 



not, indeed*, aware that this had 1 •• -» -i 1 attempted, :ill botanists & . mine I 



•i, until, in the Outlines of the Botany, . 



hazard the following theory : *• The thecse may be considered minute l< 

 same gyTate mode of development a- the ordinary leaves of the tribe; ti 

 petiole, the annulus the midrib, and the theca itself the lamina. t ; 

 united." 1 was led to this opinion, first, by the persuasion that then 

 organ in Ferns to perform a function which in flowering plant 

 tin,-,, of leaves : an !. a eondly, by the examination of viviparous si i .-,. -. 



ah >wn us (hat the leavi - • ■!' flowering plants have the pow 

 from their margin or an) point of their surface ; and in certain kii 



i found that they can produce flower-buds also. In Ferns, which 

 subject to become viviparous, the young plants ofb n grow from the Bame ; 

 apore-caa b, or from the margin ; and in a vivipai a, of which a mors 



me by Dr. Wallich. the young plants form lit 1 1. dusl - in the \ 



Upon examining these young plants, it appears that the mon 

 leaves nre preceded by still more minute primordial leavi 

 ofwhicli has nearly the same arrangement us the cellul 



mblance betwei a tin- midrib of one of th< 1 tin- ring 



striking. It i-. however, necessary to add, what is only implied in the littl< 

 which t ing extract is taken, that this explanation appl 



Ferns. With regard t.> those with striated spew r with what i> rail. 1 ;i i r.uui 



transverse ring, the) may either be considered not t" have the midrib of ti 



I of which th«' ease i- sup] osed rmed, so much dev( loj 



may be still considered a nucleus of cellular tissue, separating both from thai 

 surrounds it and also bom its internal substance, which latter a 



rules, in tin- Bame waj as the internal tissue of mi anther - - from thi 



nnder the form of pollen. Thu > confirmed by t ; 



tore of those striated eases which consist of a cluster of spore-li 

 Bssue at the base and apex, connected by extend) d 

 cellules of the Bame description, as in Gleichenia : 

 and is far from being weakened by such 



rla. In Ophioglossum another kind 

 of provision is made fox the production of sp 

 which in that genua Beam to have o" span .-.,.. 

 beyond the involute contracted segments of the 



leaf which bean them. What are called the 



thecse in Ophioglossum seem more analogous 

 the involucre ot' Mar-: 



It ha-- been thought that cur in 



Ihese plants, and different part- have i 

 pointed out as the anthers; moi aall) 



little threads which contain a grumOUS matter. 

 •ometimes < xuded in the form of a crust, and 

 spring up among the 



liability seems to have been given to the pres 

 sidered an occurrence of Mul«' ferns, principally 1 • 

 some account of which will he found in the . 

 does not appear to me that there is good evidei 



Fig. HII.— Young spore-catai and antherilU of Tc'r^diMm I 



