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plants found in all the Muscinece * and Pteridophytes * is a 
wonderful contrivance. Now the familiar fruit of the moss is, 
scientifically speaking, the second generation resulting from 
the fertilisation of the oogonium by the antherozoids of the 
antheridium. Its function is to produce spores, to guard 
them till mature, and then to disperse them. All of us know 
the pretty little urn elevated on the top of a long stalk. 
Within it the spores are developed by free-cell formation. To 
protect them the following devices occur: (1) a little thatch or 
pent-house more or less hairy, which is the remains of the 
original wall of the oogonium carried up by the growth of the 
stalk. Then comes a lid which in time opens. Then comes 
a single or double fringe of teeth, called the peristome, which 
are always in number a multiple of 4, either 4, 8, 16, 32, or 
64. These peristomes are well known as furnishing objects of 
great beauty for the low powers of the microscope. In some 
cases the inner fringe is not separated into teeth, but forms a 
beautiful lattice-work. Now, what is the object of this fringe ? 
I will give it in the language of one of the most recent writers 
on the Muscinece , Dr. Goebel (Schenk's Handbuch der 
Botanik , vol. ii., p. 399). 
“ The teeth of the peristome are very hygroscopic, their 
function is principally that of closing the opening of the 
capsule-urn in moist and wet weather, and so preventing the 
egress of the spores. In this way, on the one hand, moisture 
is not allowed to penetrate into the capsule, and so produce 
premature germination of the spores ; and, on the other hand, 
the latter cannot escape from the capsule under circumstances 
that would be unfavourable for their wide dispersion. In dry 
weather, on the contrary, the teeth of the peristome bend back, 
and so allow the fine powdery spores to escape." The word 
“ function" is here used, as you observe, but it is a mere /agon de 
parler, an evasive equivalent for “ purpose." Indeed, the learned 
Doctor just after uses the word “ purpose " bluntly (“ Der 
Zweck, die Sporen in der geoffneten Kapsel vor dem Zutritt 
von Feuchtigkeit zu schutzen, wird .... erreicht." “ The 
purpose of protecting the spores in the opened capsule from 
the access of moisture .... is reached"). But he apologises 
in a note for the indiscretion. (“Man gestatte der Kiirze 
halber diese Bezeichnung !" “This designation may be 
excused for brevity's sake ! ") Science, it seems, has its 
* The group of Muscinece , as a sub-kingdom, includes Hepaticce and 
Musci. Pteridophytes include the Vascular Cryptogams, Ferns, Horsetails, 
Club-mosses, &c. 
H 2 
