TRANSACTIONS OF SECTION D. 517 
of the statement above—which is that the long factor is the cause of the long 
pea and the absence of the long factor is the cause of the short character. This 
makes a cause which is absent do the work of another cause which is present, 
but overlooked : The absence of the long factor is the cause of the absence of the 
long character, but it is not the cause of the presence of the short. 
The fallacy lies in supposing that a cause which obscures the effect of another 
cause does something more—namely, that by its presence it annihilates the other 
cause and re-creates it again by its absence. If the moon come between the earth 
and the sun the effect of the sun is obscured, but when the moon passes out of 
line the light still comes from the sun. If a statue be placed upon a pedestal and 
the pedestal knocked away, is it the absence of the pedestal or the presence of 
gravity that brings the statue to the ground? As might be expected, the theory 
when used in analysis overlooks real recessives, and when one or more such turn 
up without their connection with their proper dominants being discovered, so 
many factors more than the case can hold are introduced. 
8. The Preservation of Specimens for Musewms by Simple Immersion. 
By A. Lor, M.D., and H. Lecaneavuevx. 
For a long time past a formula has been given for the preservation of crustacea 
without disembowelling. This last work is slow; nevertheless, it is employed in 
museums. The formula published is based on arsenic and calcium salt in solu- 
tions, with glycerine in an alkaline medium. 
We modified the formula in preparing directly arsenite of potash (neuter salt) 
and by adding to it a very weak solution of formalin in sugar, glycerine, and 
water. This process gives us the method of preserving by simple immersion not 
only crustacea, but jelly-fish, coleoptera, lepidoptera, hymenoptera, fish, and 
even hedgehog. The softness of articulations is complete and gives to specimens 
the appearance of life much greater than the ordinary method of preservation. 
The duration of immersion (two to twenty days) varies naturally, not only 
according to species, but for every specimen, according to its size. The end of 
the operation is known when the preserved specimen is taken out of the bath and 
put to dry in hot air (35° cent.) for two hours; then with a little skill it is easy 
to see if it is in good condition. 
For crustacea, lepidoptera, hymenoptera, and coleoptera a bath is quite suffi- 
cient. For fish it is better to begin by an intestinal washing. For the hedge- 
hog we think it is preferable to take out, at first, the intestinal mass, wash the 
body with formalin water, then fill it with sawdust. 
