Digestive Processes in Arachnids . By II. M. Bernard. 429 
retain their value as records of facts, they require re-stating from this 
new point of view, viz. the contents of the so-called liver-cells are 
not products of secretion, but food in various stages of digestion. 
It is worth noting that these food-globules are quite indistinguish- 
able from those found in Amoebae, which have the appearance of 
oil-drops. In neither case, however, do they consist of pure fat. 
The food-globules in the digesting cells of Araneids, according to 
Bertkau, do not darken under the action of osmic acid more deeply 
than the other parts of the cells. They do not dissolve in ether, and 
are easily dissolvable in glycerin and water. 
In the process of assimilation, these homogeneous globules become 
first finely and then coarsely granular, and are gradually transformed 
into groups of small refractive bodies which look black by transmitted, 
but white by reflected light (fig. 2). If the food-globule is small, 
one single crystal-like body is all that is left. * These so-called 
“ crystals ” are either rhomboidal, or rod -like, or they may have no 
definite form. This breaking-down of the food-globules is clearly 
indicated in Bertkau’s drawings. 
Following these crystal-like residual bodies further, we find that 
they are gradually excreted at the sides of the cells (fig. 1), and that 
here they slowly collect, to be discharged in a stream into the lumen 
of the gut, where they mix with the raw food not yet taken up by 
the digesting cells and converted into the fat-like food-globules. 
From end to end of the digesting portion of the canal, these small 
faecal bodies are to be found mixed with the sucked-in food. The 
separation is effected at the point where the canal suddenly narrows 
to form the hind-gut. Whether this long coiled tube is morpholo- 
gically the true hind-gut, I cannot say, but functionally it must be 
considered as such. At this point the epithelium suddenly changes, 
and a thick stream of the crystalline bodies is seen leaving the 
coagulated food in the mid-gut and forming into faecal masses, which 
are to be found at intervals along the hind-gut as far as the ster- 
coral pocket. In this pocket a great number of the faecal masses 
accumulate, being held back for some reason before being finally 
ejected. 
A close examination of the contents of the stercoral pocket shows 
that it consists almost entirely of countless numbers of these minute 
crystal-like bodies which in the aggregate also look black by trans- 
mitted light, but are chalky white by reflected light. The only other 
substance I could find was an occasional food-globule, whose presence 
is to be accounted for as follows. The digesting cells (as shown in 
fig. 1) are often distended to such an extent by ingested food that 
they break down. Here and there, fragments of cells and escaped 
* Cf. Mr. Moore’s paper on the Amoeba (in Ann. and Mag. Nat. Hist., Feb. 
1893), in which he considers the so-called “ crystals ” in these animals to be the 
irreducible remains of the food-globules. 
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