The hinder abdominal segments in the male show a curious asymmetrical arrangement, the sixth segment bearing on its upper side a small stalked plate (strigil) of unknown function, furnished with rows of teeth.
Other than cataclysm, asymmetrical attack, or government gone wild, we have little to worry about.
These appearances are probably due toa pathological mitosis, commonly found in cancer, in which there is an irregular diminution in the number of chromosomes; some are cast out and become degenerated or some pass over to one of the daughter cells, leaving a reduced number in the other, and thus give rise to asymmetrical mitosis.
The symmetrically substituted ureas are generally tasteless, while the asymmetrical derivatives are sweet.
Their bilateral symmetry is obviously to be regarded as primitive, and the nervous system shows an original condition from which that of the asymmetrical twisted Gastropods can be derived.
On such an interpretation, variation would result from asymmetrical division and normal inheritance from symmetrical division.
In this species the atrium is produced as an asymmetrical blind pouch behind the atriopore as far as the anus.
Ordinarily a substance composed of asymmetrical molecules is paramagnetic, but if the elementary magnets are so conditioned by their strength and concentration that mutual action between them is possible, then the substance is ferromagnetic. In all cases however it is the diamagnetic condition that is initially set up - even iron is diamagnetic - though the diamagnetism may be completely masked by the superposed paramagnetic or ferromagnetic condition.