and-on:the Seres of Mosses. 479 
dehisce longitudinally at the lateral furrows. In Buaxbaumia the theca fre- 
quently dehisces longitudinally after the manner of some anthers; whilst in 
Solanum the anther dehisces by a pore at the apex, thus approaching the or- 
dinary dehiscence of the theca. The lining of the cells, or Endothecium of 
Purkinje, may be considered analogous to the columellar membrane. In 
offering this view of the anther, it must not be understood that I dispute the 
accuracy of those beautiful laws of Morphology which are now so universally 
acknowledged. All I affirm is, that the tissue of the anther separates in a 
manner similar to that of the theca, without any reference to the origin of 
that tissue. 
Similar as is the origin of the pollen and the sporules, their appearance is 
no less so. In the very young state, it is impossible to distinguish the slightest 
difference. "They are round or triangular, &c., according to the particular 
species; they are pellucid, and they contain a few moving particles. As they 
grow older the moving particles increase in size and quantity; and the en- 
veloping membrane becomes more opake. When the pollen has arrived at 
maturity, the application of water causes the membrane to burst, and the 
moving particles to be forcibly ejected. I have frequently observed the same 
fact in sporules of the Mosses and Jungermannias; and Mr. Brown has 
recorded a similar occurrence in the Lycopodiums. After describing the 
capsules, he says, in the Prodromus Flore Nove Hollandie, p.20, “ Semina? 
ovalia, in cumulo alba, seorsim semipellucida, in aqua fovillam minutissimam 
explodentia!" It appears by the note of interrogation after “semina,” that 
Mr. Brown, with his usual sagacity, perceived something of their real nature, 
although the subject did not receive any further attention. i 
'The observations of modern botanists have thrown great light onh te func- 
tion of the pollen; and from the observations of Amici and Adolphe Bron- 
gniart in particular, * It is now known," says Professor Lindley, Introduction 
to Botany, p. 264, * that a short time after the application of the pollen to the 
stigma, each grain of the former emits a tube of extreme tenuity, not exceed- 
ing the 1500dth or 2000dth of an inch in diameter, which pierces the conduct- 
ing tissue of the stigma, and finds its way down to the region of the placenta, 
including within it the active molecules found in the grain: no one has ac- 
tually seen the tubes pass further than the placenta; but there appears to be 
