304 
The Microscope in 
[Monthly Microscopical 
Juui nal, May 1, 1869. 
in a number of specimens, as to the amount of the " secondary " 
and " tertiary " ingrowths which divide and subdivide the chambers 
in Loftusia, is very great. The principal office fulfilled by this 
accessory skeleton seems to be that of a support to the primary 
spiral lamina, imparting the necessary solidity to the organism. 
The degree of sub-division of the chambers into chamberlets seems 
to have little bearing on the general economy of the animal. 
The Author attempts to determine from the other Foraminifera 
of which the remains are found associated in the same Limestone 
with those of Loftusia, what was its probable Geological age, and 
under what conditions it was deposited ; and he thence draws the 
conclusion that the rock belongs to the lowest portion of the 
Tertiary period, presenting a microscopic Fauna very similar to 
that of some of our Miliolite limestones, but richer in the small 
arenaceous Ehizopods; and the sea-bottom was a soft Calcareous 
mud, lying at a depth of from 90 to 100 fathoms. — Bead before the 
Boyal Society, Thursday, April ^^nd. 
VII. — The Microscope in Silkworm Cultivation. By M. Corn alia. 
The report which M. Pasteur recently published, and which he 
was so good as to send me, indicates the great progress which has 
been made in this direction. Supported by a great number of 
facts, expressed with an order and clearness which an experienced 
observer can alone obtain, M. Pasteur has established it as an 
axiom that the healthy egg of caterpillars, which are themselves 
healthy, and have been carefully cultivated, should not only furnish 
a good product, but also healthy caterpillars, which in their turn 
should deposit healthy eggs. He thus proclaimed, with the authority 
of his word, the utility of the microscope, which utility I myself 
and my fellow-countrymen have contended for on all occasions 
when experiments or observations enabled us to do so. 
Indeed, for several years some of my friends have had mar- 
vellous crops of cocoons by selecting eggs free from corpuscles 
which I had selected for them after very careful investigation. 
With a microscopic examination, limited to the eggs, we make only 
a half experiment. This method is imperfect, and the incomplete 
success resulting from its employment may be attributed (excepting 
certain bad processes of culture) to examination for corpuscles in 
the eggs only, for every healthy egg does not necessarily produce 
a healthy moth. These facts are evidenced by the fact that eggs 
attacked in the proportion of 4 per cent, if proceeding from one of 
our families of moths, or 8 or 0 per cent, if from one of the Japanese 
