They are especially remarkable for the small size of the body and the extension of viscera into the legs.
The soft integument and limbs of the mesosoma have been removed as well as all the viscera and muscles, so that the inner surface of the terga of these somites with their entopophyses are seen.
Not long afterwards Lord Derby received and in March 1838 transmitted to the same society the trunk and viscera of an Apteryx, which, being entrusted to Sir R.
This is manifested by the muscular walls of the hollow viscera and of the heart, where it is the expression of a continuous liberation of energy in process in the muscular tissue, the outcome of the latter's own intrinsic life, and largely independent of any connexion with the nervous system.
In some it is very marked, for example in some viscera, the spleen, the bladder, the ureter, the uterus, the intestine, and especially in the heart.