INFUSORIA. 
61 
Meyen, in his report on Vegetable Physiology, for 1837, (p, 54 of Francis’s translation,) 
and also in his Pflanzen Physiologie, Vol. 3, p. 437, has brought forward the fact of the 
presence of starch in the Closteria, as conclusive evidence of their being plants. He states, 
that the large and snaall globules in these bodies “ at certain times, and particularly in spring, 
“ are almost wholly composed of starch.” He adds that in the month of May, he had observed 
“ many specimens of Closterium in which the whole interior substance was granulated, and all 
“ the grains gave with iodine a beautiful blue color, as is the case with starch, which is not 
“ an animal product.” 
In the Annals of Natural History for August, 1840, (No. 33, p. 415,) is given a notice of 
a paper read by Mr. Dalrymple before the Microscopical Society of London. As this paper 
gives a good idea of the present state of the discussion concerning the nature of the Closteria, 
I believe that no apology is necessary for taking from it the following extract, especially as 
my own observations enable me to confirm some of the statements and to correct others. 
The author, after detailing the history of Closterium, from its discovery by Corte in 1774, down to 
the present time, entered into a detail of its appearance and general structure: He describes it as consist¬ 
ing of a green gelatinous and granular body, invested by a highly elastic and contractile membrane, 
which is attached by variable points to a hard siliceous shell, which was afterwards stated by Mr. C. 
Varley to resist even the action of boiling nitric acid. The form of Closterium is spindle-shaped or cre¬ 
scentic ; the shell consisting of two horns, tapering off more or less to the extremities, and united at the 
central transverse line, constituting a perfectly symmetrical exterior. At the extremity of each horn is 
an opening in the shell, which, however, is closed within by the membranous envelope, wanting how¬ 
ever in some specimens. Within the shell and at the extremity of the green body, is a transparent cham¬ 
ber containing a variable number of active molecules, measuring from the 20,000th to the 40,000th of 
an inch; these molecules or transparent spheroids occasionally escape from this chamber, and circulate 
vaguely and irregularly between the periphery of the gelatinous body and the shell; further, the parietes 
of this chamber have a contractile power. The author denied the existence of any papillae or proboscides 
at this part, as well as the supposition of Ehrenberg that these moving molecules constitute the basis of 
such papillae. He also denied the statement of the same distinguished observer, that if coloring matter 
was mixed with the water in which the Closterium resides, any motion was communicated to the parti¬ 
cles of such coloring matter by the supposed papillae, or by the active molecules within the terminal 
cells. A circulation of the fluids within the shell was observed, independent of the vague movements of 
the active molecules; this was regular, passing in two opposite currents, one along the side of the shell, 
and the other along the periphery of the gelatinous body. When the shell and body of the Closterium 
was broken by pressure, the green gelatinous matter was forcibly ejected by the contraction of the mem¬ 
branous envelope. 
The action of iodine upon the specimens was very remarkable: 1st, it did not, as reported by Meyen, 
stain the green body violet or purple, but orange-brown; 2d, it produced violent contraction of the 
investing membrane of the body, whereby the green matter was often forcibly expelled from the shell at 
the transverse division; 3d, it instantly annihilated the motion of the molecules in the terminal sacs, and 
the sacs themselves became so distended with fluid as to burst and allow the molecules to escape. 
The mode of reproduction was stated to take place, 1st, by spontaneous division; 2d, by ova; 3d, by 
interbudding, or the conjugation of two Closteria. 
