THE YOUNG NATURALIST. 



308 



was taken in this country it would not be 

 considered a very striking aberration. 



Parasites-— Exohista vulgaris (PI. 3, Fig. 

 3c.) already named as attacking A. cardamines 

 Dr. Meade informs us has been bred from 

 this species. A species of Pteromali (PI. 5, 

 Fig. ic) has also been bred from the pupa of I 

 Kapv by Mr. Thompson, oi Coventry, but we 

 ire unable at present to name it. Since the 

 Heath of Mr. Walker no one has taken up 

 this branch of Entomology, and the species 

 are so exceedingly variable as to make their 

 determination a matter of considerable 

 difficulty. 



ON THE STUDY OF 

 MOSSES. 



By Chas. P. Hobkirk, F.L.S., (Vc. 

 (Editor of the Naturalist. Author of a 

 Synopsis of the British Mouses, &e.) 



Although the mosses are ranked among I 

 the lower orders of the vegetable world, they j 

 are yet among the most beautiful and in- 

 teresting objects to the botanist who engages I 

 in the study of them. It is in the hope of j 

 inducing some of the young botanical readers 

 of this journal to study them that I have 

 undertaken, at the request of the Editors, to 

 eontribute a few simple notes upon them to 

 its pages, and these notes I shall endeavour 

 to make as plain and as intelligible as I 

 possible. Without at present considering 

 the question of their reproduction, on which ; 

 I may have somethiug to say hereafter, I 

 will at once proceed to give you some idea of 1 

 the structure and of the different parts of a | 

 moss. 



If any of you go into some of our rich 

 woods any time about April or May, you I 

 jannot fail to find growing at the roots of 

 trees, or on most shady banks, the widely 

 spreading bright green tufts of one of our 

 prettiest mosses — Milium hornum. This is j 

 sufficiently common and widely distributed to 



be found by almost any of you. Now take a 

 tuft home with you. and there separate a 

 single plant from the rest, and examine it. 



You will rind each single pk nt when fully 

 grown to be about from one to three inche:. 

 in height, closely covered with bright gree: 

 leaves. Tear a few of these leaves off the 

 stem on a glass slide, and place them unde - 

 the microscope, you will then see even under 

 a low power, that they are saw-toothed 

 (serrulate) along the edge or margin, which 

 will also appear somewhat thickened (mar- 

 gined J, and that each possesses a midrib 

 running from base to apex, where it is lost 

 in the thickened margin. On increasing the 

 power of your object glass, you will further 

 find that each of the teeth of the margin is 

 double, one generally pointing forwards and 

 the other backwards : and that the tissue of 

 the leaf (Areola j is composed of large cells, 

 semi-transparent, in some mosses they are 

 very small and dot-like, but in all the species 

 of the genus Mnium they are very large. At 

 the top of some of the stems you will find the 

 long-stalked fruit. Take this off, and examine 

 it. The stalk (seta) is generally from one to 

 two inches long, and crowned at its summit 

 with the fruit {theca ox capsule). If sufficient!) 

 young you will find this partially enclosed by 

 a thin mmbraneous veil (calyptrx), and when 

 this is removed, the capsule will be found to 

 be closed by a convex lid (operculum ) tipped 

 with a small point. When the capsule h 

 ripe this lid falls away, and discloses to view 

 a magnificent ring of beautiful teeth (peris- 

 tome). The outer ring is composed of sixteei, 

 teeth, densely barbed, and there is also an 

 inner ring, or membrane, deeply divided into 

 sixteen orange colored processes, with an 

 equal number of very thin hair-like processes 

 termed cilia. It is chiefly upon the form, 

 number, and arrangement of these teeth thai 

 the various genera of mosses are discrim- 

 inated. These are some of the principal 

 parts of a moss, there are others which in 

 some future paper, I shall hope to brin,c 

 before your notice in different species. 



