298 Sketch of the Infusoria of the family Bacillaria. 
Meyen, in his Report on Vegetable Physiology, for 1837, (p. 
54 of Francis’s translation,) and also in his Pflanzen Physiolo- 
gie, Vol. III, 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 small. globules in these bod- 
ies “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 eer as is the case with starch, which is 
not an animal 
In the Annals of Natural History for August, 1840, (No. 33, 
p- 415,) is given.a notice of a paper read by Mr. Dalrymple be- 
fore the Microseopical 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 obser- 
vations enable me to confirm some of the statements and to cor- 
rect others. 
“The author, after detaiting the history of Closterium, from its dis- 
covery by Corte in 1774, down to the present time, entered into a detail 
of its appearance and general structure; he described it as consisting 
of a green gelatinous and granular body, invested by a highly elastic 
and contractile membrane, which is attached by 1 variable points toa 
hard siliceous shell, which was afterwards stated by Mr. C. Varley #6 
resist even the action of boiling nitric acid. The form of Closterium 
is spindle-shaped or crescentic—the shell consisting of two horns, taper 
ing off more or less to the extremities, and united at the central trans- 
verse line, constituting a perfectly symmetrical exterior. At the ex- 
tremity of each horn is an opening in the shell, which, however, 
closed within by the membranous envelope, wanting however in some 
specimens. Within the shell and at the extremity of the green bodys 
is a transparent chamber containing a variable number of active mole- 
cules, measuring from the 20,000th to the 40,000th of an inch ; these 
molecules or transparent , occasionally escape from this cham- 
ber, and circulate vaguely and irregularly between the periphery of the 
gelatinous and the shell; further, the parietes of this chamber 
have a nee power. ‘The author denied the existence of any 
a or proboscides at this part, as well as the supposition of Ehren: 
berg that these moving molecules constitute the basis of such papille. 
He also denied the statement of the same ¢ stin ished observer, that 
if coloring matter was mixed with the water in which the 
