and on the Sexes of Mosses. 48] 
that the embryo requires, no preparation to enable it to perform its func- 
tions. 
But, taking into full consideration the facts above narrated, we cannot 
but conclude that in the Ce/[ulares, a provision similar to that of the pistillum 
in Vasculares, does not exist,—the former being capable of reproduction by 
the mere ejection of its pollen or sporules on the soil. 
Professor Lindley has drawn an ingenious analogy between the parts of 
fructification in Mosses, and the flower of Vasculares. He argues, that the 
peristome and calyptra are modified leaves, obeying the received laws of 
morphology. Not having an opportunity of examining the proofs, which he 
draws from examples in the cotyledonous plants, I cannot enter on this sub- 
ject with any chance of either disproving or confirming his opinions. I can, 
however, bear testimony to the opinion thatthe calyptra is a modified leaf. 
Any one who had seen the young leaves of Tortula ruralis growing amongst 
the pistilla would be struck with the similarity of their ‘appearance. If the 
small portion of lamina at the base of the excurrent nerve were folded 
inwards, and united at the margin, it would be almost impossible to distin- 
guish the leaf from the calyptra. Dr. Greville, in his beautiful Scottish 
Cryptogamic Flora, has unintentionally given a good proof of this fact. His 
figure of the calyptra of Leskea polyantha has two nerves at the base, opposite 
the fissure, precisely similar to those which are found at the base of all the 
leaves in the plant. 
Since this paper was read to the Society, I have been informed by Mr. Brown 
that Dr. Mohl has recently published some “ Observations on the Development 
and Structure of the Sporæ of Cryptogamous Plants ;” a translation of that 
part which relates to the Mosses he has most kindly furnished me with. 
Dr. Mohl describes the cavity between the columella and columellar mem- 
brane as being occupied, in an early state, by an extremely delicate cellular 
tissue, the cells of which lie in horizontal rows, and contain small granular 
masses, the rudiments of the future sporze. In most Mosses, he states, the 
spore are four in each mother cell, and they are arranged in a tetrahedral 
union. He fancied that, in some of the cells, he discovered more than four 
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