Dr. Hanstein on Fecundation and Development in Marsilea. 417 
3. Mandibles falciform, with the inner margins smooth, but 
presenting impressions of denticulations; outer margins 
with a projecting haft (contre-fort). 
A. erythrinus ; A. falcarius ; A. Manticorus. 
4. Mandibles falciform, with the inner margins denticulated, 
and with no projecting haft on the outer margins. 
A. Trigl; A. Scarites; A. Lupi; A. rapax ; A. verrucosus. 
XLV.—On the Fecundation and Development of Marsilea. 
By Dr. Hansrrin*. 
WueEn the task was set me of reporting to the Academy upon 
the capability of development of the so-called Nardoo-fruits 
(the capsules of an Australian species of Marsilea), and upon 
the processes observable in it, 1 was unable to trace either the 
fecundation or the development of the germ-plant upon the few 
fruits first sent by Alexander Rose, as nearly all the prothallia 
remained unfertilized. Since then I have succeeded in repeated 
sowings, for which fruits sent by Mr. Osborne, of Melbourne, 
and by Dr. Ferdinand Miiller, of the Botanic Garden at that 
place, were employed, in witnessing the reproduction and germi- 
nation of this genus, which were previously unknown. 
About four hours after the micro- and megaspores have es- 
caped into the water in the manner formerly described by mef, 
and issued from their sporangia, the first alterations are per- 
ceptible in them. In the small androspores the contents, of 
starch and proteine-substance, have then formed a more homo- 
geneous plastic mass, and become somewhat contracted all round 
from the margin, leaving only a few granules on the latter. 
This mass is then quickly divided, by three planes of segmenta- 
tion perpendicular to each other, into eight equal parts, and 
each of these is immediately broken up in two directions, differ- 
ent from each other and from the previous directions of division, 
into four parts, disposed in relation to each other in the manner 
of the angles of a tetrahedron. In this way thirty-two equal 
portions of protoplasm are produced by an act of division which 
resembles the process of segmentation in the animal ovum; and 
it is only after the completion of this that a cell-membrane is 
formed around each of them. 
In each of these thirty-two cells, which retain their regular 
arrangement, a spermatozoid is developed. The four spermato- 
zoids of each tetrahedral group lie in the approximated halves of 
* Translated by W.S. Dallas, F.L.S., from the ‘ Monatsbericht der 
Akademie der Wissenschaften zu Berlin, August 1864, p. 576. 
+ Monatsber. Berl. Akad. 1863, p. 414. 
Ann. & Mag. N, Hist. Ser. 8. Vol, xiv. 27 
