1885.] 
Analyses of Books . 
299 
of these animals has been greatly enhanced by the continuous 
and close observation which his experiments required.” 
A few words are then written in justification of science as against 
those worst abortions of a neuropathic age known as Bestiarians, 
Zoophilists, Humanasters, &c. These worthies hold, for some 
reason incomprehensible to all but themselves, that whilst the 
infliction of pain and death upon animals for other purposes is 
justifiable, yet if in pursuit of knowledge it is a “ horrible sin.” To 
the stale Old Bailey quibble that “ two blacks do not make a 
white we reply that in the laboratory they occasionally do, and 
that even when they do not it has long been held ridiculous for 
the kettle to stand forth and denounce the pot. 
In his first chapter the author gives a brief description of those 
features in the anatomy of the Medusa? which are necessary for 
an understanding of his researches. He calls especial attention 
to these animals as displaying in the cover of their manubrium 
and in the lining of the umbrella true contractile tissue. We 
have, in other words, here the first appearance of muscular fibre, 
the same thing may, according to the author’s investigations, be 
said of nerve-tissue, though so eminent an authority as Professor 
Huxley declared in his “ Classification of Animals ” that “ no 
nervous system has yet been discovered in any of these animals.” 
Mi. Romanes insists on the characteristic necessary for distin- 
guishing muscle from nerve. A stimulus, namely, applied to a 
nerve ess muscle can only pass through the muscle by occasioning 
a visible wave of contraction. A ne.rve, on the contrary, conveys 
any stimulus without any visible movement or change of shape. 
In the next chapter we find an account of the author’s funda- 
mental experiments. The results he himself summarises as 
follows : In the naked-eyed Medusa the removal of the extreme 
periphery of the animal causes instantaneous, complete, and 
permanent paralysis of the locomotor system. In the genus 
Sarsia, indeed, the principal locomotor centres are the marginal 
bodies, though every minutest portion of the spaces of the margin 
between the tentacles has the property of setting up locomotive 
impulses. 
Among the covered-eyed Medusa the margin is, indeed, the 
principal, but not, as in the former group, the exclusive seat of 
spontaneity. . Hence, though the removal of the margin destroys 
the spontaneity of the creature for a time, yet the paralysis thus 
produced is seldom permanent. 
Even after the removal of their locomotor centres all the 
Medusa respond to mechanical, chemical, luminous, thermal, 
and eledtric stimulation. The sense of sight is demonstrably 
present, e.g., in Sarsia. The marginal bodies subserve the visual 
function, but the author prudently declines to assert that they are 
so fully specialised as sight organs as to be incapable of minis- 
tering simultaneously to any other sense, The ultra-red heat- 
rays were not found to have any effect upon these visual organs, 
