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PROGRESS OF MICROSCOPICAL SCIENCE. 
the vibrios, but which afterwards permitted the vibrios to increase 
more rapidly than in the standard albumen-solution: — Bleacliing- 
powder, bichloride of mercury, chlorine-solution, caustic soda, acetic 
and nitric acids, sulphate of iron, and the sulpho-carbolates of potash 
and soda. The sixth class contains those compounds which exercised 
no action on the animalcules, either at first or after sixteen days : — 
Arsenious acid, common salt, chloride of calcium, chlorate of potash, 
sulphate of lime, bisulphite of lime, hyposulphite of soda, phosphate 
of lime, turpentine, and pepper. The seventh class includes those 
substances which favour the production of animalcules and promote 
putrefaction : — Lime, charcoal, permanganate of potash, phosphate of 
soda, and ammonia. 
Structure of Normal and Varicose Veins. — The ‘ Lancet’ of July 13th 
states that Dr. S. Soboroff has lately undertaken a series of researches 
on the structure of healthy and varicose veins, the results of which 
possess considerable interest. He had at his disposal eight specimens 
of varicose veins, which, with only one exception, were accompanied 
by pathological changes in the vena saphena. These were all 
capable of being arranged in two groups : in both the lumen of the 
vessels was greatly enlarged ; but in one the walls were thickened, 
in the other they were attenuated. The preparations seemed to have 
been made with great care, some being silvered to show the epi- 
thelium ; others subjected to the action of chloride of gold, chloride 
of palladium, and chromic acid. The principal fact that he has 
definitely ascertained is that a dilated venous trunk, even when pos- 
sessing almost perfectly transparent walls, contains colossal muscular 
fibre-cells. These are so large that when first observed they were 
regarded as fasciculi of unstriped muscle, but more careful examina- 
tion, aided by staining experiments, showing the well-marked outline 
of the cells and the rod-shaped nuclei, clearly demonstrating that 
fibre-cells alone were under the microscope. The adventitia of the 
dilated veins was thin and but sparingly supplied with vessels, and 
the epithelial lining of these attenuated vessels was apparently con- 
tinuous and unaltered. In the thickened and dilated veins, on the 
other hand, the adventitia was hypertrophied, and the vessels dis- 
tributed to it were large and numerous. 
A Fossil Hydractinia. — Professor George Allman, F.R.S., in a com- 
munication to the ‘ Geological Magazine ’ for August, says, that among 
the very few known instances of fossil hydroids, the genus Hydractinia 
must be included. Under the name of Cellepora echinata, M. Michelin 
has described a fossil from the Subapennine group of Asti, and from 
the Superior Fallimian of Bordeaux and Dax.* M. Fischer has drawn 
attention to the fact that the Cellepora echinata of Michelin is really a 
Hydractinia encrusting a Murex or a Nassa, while he has himself added 
another fossil Hydractinia from the Upper Greensand of Mans.f This 
he found in the collection of M. Ale. d’Orbigny, where it encrusted 
numerous specimens oiNatica tuherculata, d’Orbig., from that formation. 
* Michelin, ‘Icon. Zooph.,’ p. 74, pi. xv., fig. 5. 
t Fischer, ‘ Bull, de la Soc, Gie'ol. tie France,’ 2 mc ser., t. xxiv., p. 089. 
