178 Proceedings of Royal Society of Edinburgh. [sess. 
be referred to molecular radiations from the uterine to the pneumo- 
gastric centre. Usually, however, in the course of a few months, 
through the agency of habit, the pneumogastric centre becomes 
tolerant, and the symptoms evidencing disturbance in this centre 
coetaneously disappear. It is difficult to understand why the sick- 
ness should be experienced, more especially, although not solely, in 
the morning. It is quite possible that the change from the recumbent 
to the erect position may after sleep render the whole nervous system 
more liable to explosive disturbances. The state of the stomach, too, 
may also aid in determining this somewhat anomalous phenomenon. 
Frequently we find epileptic patients who suffer only from their 
disturbances on assuming the erect position after sleep. The ano- 
malous phenomenon, therefore, as it occurs in the pregnant woman 
is not without a parallel. The more highly unstable the nervous 
system is generally, the more likely is a woman when she becomes 
pregnant to suffer markedly, and for a lengthened time, from sickness, 
whether matutinal simply or more or less constant. It is well, 
however, to remember that the inherent tone of the uterus itself 
will affect materially the molecular radiations engendered by the 
developing germinal mass, and transmitted through the agency of 
the uterine tissue to the nerve centre. The resulting disturbances 
will be correlatively augmented or diminished according as the tone 
of the uterus is high or low. 
On the so-called “ Liver ” of Carcinus mcenas. By Dr A. 
B. Griffiths, F.RS. (Edin.), F.C.S. (Lond. and Paris), Mem- 
ber of the Physico-Chemical Society of St Petersburg, &c. 
(Read February 4, 1889.) 
“ A true knowledge of biology must be based on a knowledge of chemistry 
and physics.” — M. M. P. Muir. 
This memoir details a continuation of the author’s investigations 
on the physiology of the Invertebrata. At this point we consider 
the physiological functions of the so-called “ liver ” of the Brachyura. 
Was it not M. Letourneau, in his La Biologie , who said, 
“ Does the pancreas exist in the invertebrates % This is a question 
of comparative physiology which still waits for a reply. We have 
seen that we do not begin clearly to recognise the pancreas except 
