ANDREWS: ANNULUS VENTRALIS. 
475 
and slender in C. clarkii for that form of annulus rather than short 
and stronger as in C. afpnis, and it is not evident why two such similar 
annuli as those of C. bartoni and C. immunis should have such very 
diverse stylets as are found in the males of those species. Whatever 
causes determine the general appearance of the species, the length 
and slenderness of the chelae, the sharpness of rostrum and of spines, 
or the reverse, may also produce much of the specific form of the 
stylets without reference to the utility of the forms so determined. 
May we not assume similar factors at work producing the right- 
and left-handed annuli in individuals of a species; the specific forms 
of annuli and stylets in species of one genus; and the original formation 
of the similar sperm receptacles in such distant relations as Cambarus 
and Homarus? Some unknown changes in the eggs may, like a 
slight turn of a kaleidoscope, convert right- into left-handed symmetry 
as it finally appears to us in the resultant product, the annulus. Occa¬ 
sionally some not dissimilar changes might shift the symmetry of the 
egg organization into what would appear finally as a new specific form 
of annulus, if that egg should become a female, or a new specific form 
of stylets if a male, since the male and female organizations are 
symmetrically related, alternative arrangements necessarily coordi¬ 
nated as are the organs within one individual. 
The specific forms of annuli and the annulus itself would thus have 
come into sight as mutations. 
Methods. 
The annuli, with sometimes much neighboring tissues, were removed 
and fixed variously, with heat, Worcester’s liquid, picrosulphuric, 
Perenyi’s, Flemming’s, Gilson’s liquid, or with formalin. The best 
results for detection of sperm on the surface were got by Flemming’s 
strong solution followed by Perenyi’s liquid and Conklin’s stain. 
Paraffin sections then showed black sperm in a gray coagulum, if the 
annulus had been treated with egg albumen to retain the sperm. 
In material fixed in Morgan’s picrosulphuric, followed by Perenyi’s 
liquid and Conklin’s stain, sections showed the sperm red, the wax 
plug bright yellow, the nuclei of the epidermis and connective tissue 
blue, the lining of the trumpet brown, the exoskeleton toward the 
cavity reddish, and the outer layers clear and colorless. 
