420 
PROCEEDINGS OF THE SOCIETY. 
was becoming one of very serious import in some of our colonies, so 
much so indeed that it behoved Government to give it careful attention. 
Mr. H. M. Bernard gave a resume of his paper * On the Digestive 
Processes in Arachnids,’ illustrating his remarks, as he proceeded, by 
diagrams drawn upon the blackboard. 
Prof. Bell said they were greatly indebted to Mr. Bernard for his 
very interesting communication which appeared to open up a new field 
of observation. Of course, as Mr. Bernard had seen the preparations to 
which he had referred, he was in a better position to form an opinion 
than those who had only heard them described, but without seeing them 
one was inclined to ask whether after all there was not likely to be 
some mistake. If this were not so, it would appear that digestion was 
not confined to the digestive tract as usually understood, and in that 
case it might be that they were at the beginuing of a series of observa- 
tions which would throw a new light upon the subject of the digestive 
processes. He hoped that Mr. Bernard would be able to continue his 
observations until he arrived at facts which might be of great physio- 
logical importance. 
The President said he had never worked much on these groups, 
except amongst the Acarina. With regard to the so-called “fat-body,” 
he took it to be the brown coating of cells which many of the German 
writers had termed the “ liver stomach.” Of course the question was 
what was the function of this coating of brown cells ? The old idea 
that they were liver cells had been disputed and materially shaken, and 
Professor Pay Lankester was of opinion that they had a blood-elabora- 
ting office. With regard to the crystals, there was no doubt that they 
did exist in large quantities, and that they accumulated so much as 
actually to show through the skin in a definite pattern ; in fact at one 
time, before this was recognized, numerous species were named from them 
by those who regarded them as distinctive markings. It was a curious 
thing that the distribution of these crystals was by no means the same 
in different families of Acarina ; in the majority of cases they lay out- 
side the canal altogether, and were not found inside at all until they 
reached the hind-gut. In the Gamasidse they were poured into what 
Mr. Bernard called the stercoral pocket, or cloaca, entirely from the 
Malpighian vessels, which were two only in number. That was the name 
they always went by, and though it was quite possible that they were 
the analogues of the Malphigian vessels, it by no means followed that 
they were the homologues, because they entered into the narrow portion 
of the hind-gut or cloaca just before it entered the stercoral pocket. In 
the rectum there was a short narrow portion and just at that part the two 
Malphighian vessels poured out their contents into it, and it was from 
them alone that, in the Gamasidm, these crystals proceeded. On the 
other hand there were other families, such as the Tyroglyphidm, where 
these crystals apparently never entered the hind-gut at all, but were 
spread through the general body-cavity, there being no definite channel 
by which they escaped ; they did not appear to accumulate, but were 
spread about the body-cavity in small masses and they were more or 
less stored up in the body, and were probably never got rid of at all. 
