334 
NOTES AND MEMORANDA. 
form of ji little baud folded into a loop upon itself. The convex part 
of the angle projects more and more outside the body and becomes 
wider. One of its parts, which is na rower than the other, soon dis- 
engages its extremity from below the base represented by the first 
prolongation of the cellular body. Frmn the time of this disengage- 
ment the little band, more or less straightened, has the general form of 
the tentacle and moves by slow undulations and distortions. At hrst 
yellowish, like the substance of the cellular body from which it is 
derived, in a few hours it becomes greyish and striated. It is after its 
formation that the infundibular depression of each new individual and 
the flagellum which accompanies it are formed. 
The movements of the tentacle always remain slow and continuous, 
as if they were due to sarcodic contractions, whilst those of the flagellum 
take place alternatively by inflections and undulations, either wide or 
very short, slow or extremely rapid, then simulating a true vibratory 
movement, and with periods of inaction t)f irregular duration. Both 
these modes of activity as well as the sarcodic contractions, which are 
always slow, of the interiiiil fllamonts of the Noctilucae, are not in any 
way modified by induced currents, even powerful ones, nor by the 
making and breaking of the continuous currents. M. Cadiat and I 
have proved that such is also the case with the body, the pedicle, the 
cilia, and the j)ulsatile vesicle of the Vorticellm, and for the homologous 
parts of the other Infusoria and Amoebm, as long as the water and its 
salts are not decomposed. When this decomposition takes place 
under the influence of continuous currents these ditterent movements, 
quickened for some minutes, cease at the same time that the animal 
dies.* 
The Functions of Leaves. Part played hy the Stomata in the 
Exhalation and Inhalation of Aqueous Vapours hy the Leaves. — The part 
played by the stomata in exhalation by the leaves may be deduced 
a priori from the permanently open state of their ostioles, which are 
thus always ready to allow the issue of the vapours formed in the 
intercellular passages, from which they pass into the sub-stomatic 
air-chambers. In order to show that the vapours exhaled do really 
follow this course, I have tried to make them act, immediately on 
leaving the leaf surface, on sensitive hygrometric paj)ers on which 
they would make an imj^ression at the points of issue, so as to show 
exactly the position of the latter. 
Of the various hygrometric papers which are available for this 
purpose, that which has seemed to me the best has its sensitive layer 
formed by a mixture of perchloride of iron and chloride of palladium, 
obtained photo-chemically. Of a yellowish white tint whilst dry, it 
passes into black by darker and darker tints, in proportion as it 
becomes damper, and when it has received a hygrometric impression, 
it is easily fixed by simple washing in a solution of perchloride of 
iron. 
When we wish to ap^Ay it to the study of the foliar exhalation, a 
fold is made in the paper, into which is introduced and retained by 
* M. Ch. Robin, in ‘ Comptes Rendus,’ vol Ixxxvi. p. H82. 
