1888-89.] Mr Irvine & Dr Woodhead on Carbonate of Lime. 331 
into the phosphate, and are so carried in the lymph (see “Analysis 
of Lymph,” in Appendix). It is to he noted, however, that these 
gastroliths are not found in the other decapods ( Braehyura ), so that 
any reserve store can not be in the stomach, but if present at all, 
and we see to what a very slight extent this can take place from 
the analysis, it must be in the lymph, where it is chiefly in the form 
of phosphate of lime. 
We think that this theory may be dismissed as of comparatively 
little importance, as, even if the teeth and whole inner calcareous 
structure could be absorbed by the animals, the amount of carbonate 
of lime at their disposal from this source is so small (a very small 
fraction of the outer covering) that it could not account for any 
material part of the new structure. Consequently such an explana- 
tion must be abandoned. As a matter of fact this internal structure, 
consisting of teeth, plates, &c., is not materially affected during 
the process of ecdysis where the other changes are so well 
marked. 
The radical change caused by ecdysis is very striking. The 
animal in the operation shedding or throwing off the whole of its 
outer calcareous shell or structure, along with the branchiae and 
calcareous supporting plates, at the same time the bulk of the fleshy 
muscular matter is much increased, so much so that we ask with 
astonishment could the animal have ever existed in the discarded 
structure? We failed to find, immediately after ecdysis, carbonate 
of lime on any of the outer surfaces of the body, but, as already 
noticed, the abdominal calcareous structure is not materially 
affected. 
The method we used to determine the amount of carbonate of 
lime and chitinous matter was as follows The flesh was separated 
as carefully as possible from the exo-skeleton and the latter was 
dried and treated with weak nitric acid, by which the inorganic 
matter was dissolved out. The chitinous matter left was well 
washed and dried. The, lime and phosphoric acid were determined 
in the solution. In Appendix will be found a number of Tables 
(III., IV., and Y.) in which are given the proportions of carbonate 
of lime and chitinous matter present in the different portions of 
the structures of these animals, and also the composition of the 
stomachical teeth. 
