7G FILICALES. [Acrogens. 



connected with hybrid action ; and I agree with Link, in Ins first view of the question 

 tha tl'e fu • ' ut the Antheridia rJulum sit perspectaet dedarata, an opinion which 

 faVhThWe^ since abandoned in favour of these bodies being anthers. Ihey may 

 be bodies andozous to anthers ; but if so they have none ol their structure. 



V i I to Is- mentioned that the spiral threads, with an active motion already 

 J,£ , Mosses, also exist in some Ferns. He found them abundantly in the 

 ^ern ii,' 1 af of ^pidium augescens, and elsewhere, traced their development and 

 u e Z 59 that thev a'r, produced among the earnest ceUs that go to the composition 

 ofa fern-leaf. («■■ S-hkUU-n and Niigeli, Zeitsckrift furWmensch. Bot s. 1. 168*. 4.) 



The stems of ferns, when arborescent, are objects of great interest to the botanist 

 partiv on account of heir rarity, secondly, because of their singular structure and 

 cCcia .:,„-, they offer the highest form of development in Flowerless Plants. 



1 , « been till lately that they have been well understood ; they have now , however, 



received full illustration from Mohl, in Martius's beautiful Icones Plantarum Crypto- 

 )^;J t ,n I »ne of the most interesting of them is that of the Baranetz or Barometz, 



wZhe Scythian Lamb, in which,by cutting off the eaves except a sma 1 portion 

 of the stalk, of a woolly-stemmed species, and turning it upside-down, simp e people 

 have been persuaded that there existed in the deserts of Scythia creatures half animal 



Th P e veins of the leaves of Ferns have been sometimes described as dichotomous ; it is 

 only however, in a certain number that this peculiarity occurs. In some they are 

 simple, iu others they are collected in lozenge shaped meshes, and m some they are 

 .rill differently arranged. Langsdorf and Fischer seem to have been the first to pay 

 attention to these peculiarities, which have been admirably applied to the characters of 

 genera by Adolphe Brongniart and Presl, who have shown them to be of the first 

 importance in distinguishing genera. 



Bory de St. Vincent elevates Ferns to the rank of a class, intermediate between 

 Monocotyledons and Acotyledons ; but at the same time he attaches no importance to 

 the descriptions of those writers who, having seen the germination of the sporules, have 

 attempted to prove an identity between them and Monocotyledons m that respect. He 

 justly ni^Tves, that the irregular unilateral scale which lias been seen to sprout forth 

 upon the first commencement of their growth is extremely different from the cotyledon 

 of Monocotyledons, which pre-exists in the seed and never quits it, but swells during 

 germination, and acts as a reservoir of nutriment for the young plantlet. He most 

 properly regards it as an imperfectly developed primordial leaf. 



' In some modern books of Botany Ferns are broken up into several distuict 

 natural orders, which in my opinion are not to be maintained. But it does appear 

 that three essentially distinct groups exist among them. Of these the largest portion 

 consists of what were once named " dorsiferous ferns," in all which the spore-case is 

 furnished with an elastic ring or band ; in two other groups, of inconsiderable extent, 

 the spore-cases have no such band. In one of them the cases are often immersed m 

 the tissue of the back of the leaf, and partially, or entirely, united by their touching 

 edges into many-celled bodies ; in the other, the spore-cases appear to be notlimg more 

 than an alteration of the edge of a contracted leaf. Hence arise the three following 

 orders : — 



Natural Orders of Filicals- 



Spore-cases rtnglm, distinct, 2-ralred, farmed on the margin of a~[ ^ Ophioglossace*:. 

 contracted leaf J 



Spore-cases ringed, dorsal or marginal, distinct, splitting hre- "I 24 _ p OLY poDiACE«. 



gularly J 



Spore-cases ringlcss, dorsal, connate, splitting irregularly by «1 05 Dan.EA.CRS. 



ventral chj't J " 



No part of Mr. Henfrey's report is of greater interest than his skilful description of 

 the alleged facts published concerning Ferns by numerous modern observers ; and 

 although it is in some degree a repetition of what these pages already contain, yet it 

 deserves to be quoted at length. 



" This class formed, for a long time, the great stumbling-block to those who sought 

 to demonstrate the existence of sexuality in the Cryptogamous plants. The young 

 Capsules were generally considered to be the analogues of the pistillidia of the Mosses, 

 and the young abortive capsules, which frequently occur among the fertile ones, were 

 -upposod by soine authors to represent the antheridia. Mr. Griffith, shortly before 



