ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
55 
Mechanism of Sucking in Suctoria.* * * § — Herr J. Eismond urges certain 
objections to the suggestion of R. Hertwig that the sucking mechanism 
depends on a shortening and subsequent elongation of the sucking 
tentacles. Observation, however, shows that these tentacles often remain 
quite stiff, and it is difficult to see how the food would not be ejected on 
the contraction of the tentacle. We must suppose that the tentacles 
play only a passive part, and seek elsewhere for the mechanism. It is 
suggested that it is to be found in the relations of the body-plasma to 
the outer world ; where there is a diminution of pressure there must be 
a centripetal streaming into the sucking tubules, and so into the body. 
This is brought about by the contractile vacuoles, the activity of which 
must play the chief motor part in the sucking mechanism of the Suctoria, 
and, partly, in the swallowing mechanism of the Ciliata. What the 
author imagines to happen is, that as the contractile vacuoles pump out 
watery excretion-products from the body-plasm they act as aspirators, 
for in their diastole they diminish the turgidity of the body, and con- 
sequently produce an ascensive pressure in the sucking tubules. 
Amphileptus flagellatus.t — Mr. C. Rousselet, under this name, 
describes a new species of Infusorian, which he has often found at 
Keston. It is 1/65 to 1/55 in^in size including flagellum, with a width of 
1/100 to 1/120 in. At first sight it might be taken for an abnormal 
Trachelius ovum , but it is a true Amphileptus , distinguished from all 
the known species by its large size and its prominent and long trunk- 
like filament. The body is highly elastic and changes its form and 
withdraws its flagellum on the slightest pressure. The flagellum is 
carried in a graceful spiral curve in front of the body, when the creature 
is swimming. 
The Genus Conchophthirus.J — Prof. G. Cattaneo gives an account 
of the interesting Holotrichous Infusorian Conchophthirus anodontse found 
on the gills of freshwater mussels. He discusses the synonymy of the 
genus, describes the animal and its movements, finds only one species 
in the bivalves, and gives reasons for believing that the Infusorians 
accompany the Glochidia when they leave the mother mussel. 
Gigantic Specimens of Actinosph8erium.§ — Mr. S. Calvin has 
found near the State University of Iowa some Rhizopods which are 
distinctly visible to the naked eye. They are probably examples of 
Actinosphserium Eichhornii. But whereas the maximum diameter given 
by Leidy is 0*85 mm., there are scores in Mr. Calvin’s jars more than 
0’75 mm., and the largest specimen measured had a diameter of 
1 • 36 mm. 
Structure and Development of Spores of Myxosporidia.||— M. P. 
Thelohan finds that the nucleus of Myxosporidia divides by karyokinesis. 
The polar capsules are formed at the expense of small masses of proto- 
plasm which are differentiated in the sporoblast and inclose a nucleus ; 
the mechanism of their formation presents many analogies with that 
* Zool. Anzeig., xiii. (1890) pp. 721-3. 
t Journ. Quek. Micr. Club, iv. (1890) pp. 114-5 (1 fig.). 
t Rend. R. 1st. Lomb. Sci., xxii. (1889) pp. 604-14. 
§ Araer. Natural., xxiv. (1890) pp. 964-5. 
|| Comptes Rendus, cxi. (1890) pp. 692-5. 
