612 D. KEILIN 
independently Valery Mayet (18, 1896) has shown that in 
Cerambyx larvae, of the six Malpighian tubes, four are 
larger and are filled with calcium carbonate. The excretion 
of this product, which was described by Valery Mayet as a new 
function of the Malpighian tubes, was denied by Kiunckel 
d’Herculais (10, 1896), who at a meeting of the Entomological 
Society of Paris made an observation that Valery Mayet 
probably misunderstood the anatomy of the larva, and that 
the organs containing calcium carbonate were not Malpighian 
tubes but the intestinal caeca. Later, Valery Mayet (14, 1896) 
succeeded in demonstrating that the tubes in question were 
actually the Malpighian tubes; iunckel d’Herculais then 
suggested that the calcium carbonate of Cerambyx larvae 
is probably formed in other special glandular cells, and that 
the Malpighian tubes were eliminating only the excess of this 
product. P. Marchall (12, 1896), who took part in this discus- 
sion, observed that the excretion of CaCO, by the Malpighian 
tubes has nothing surprising in it ; he thought, however, that 
the excretory function in insects is not localized in one particular 
organ: uric acid, for instance, can be found not only in the 
Malpighian tubes but in the intestine and the fat body. 
Calcium carbonate has been found also by Vaney (19, 1900 ; 
20, 1902) in the anterior pair of the Malpighian tubes of the 
Stratiomys larva, and by Pantel (16, 1898) in the parasitic 
larvae of Tachinidae and in the larvae of Ptychoptera 
(17, 1914). In the latter, two of the five Malpighian tubes 
are transformed into large sacs filled with calcium carbonate. 
I myself have found the excreted calcium carbonate in the 
Malpighian tubes of many Dipterous larvae: Hristalis 
tenax, L., Myiatropa florea, L., Mallota erista- 
loides, w., Merodon equestris, F., Syritta 
pipiens, L, HEumerus strigatus, Flin, Ptycho- 
ptera contaminata, L., several species of Stratiomyidae 
belonging to the genera Stratiomys, Sargus, and 
Odontomyia, and among the Trypetidae in Anastrepha 
striata, Schiner. In all of these larvae the carbonate- 
containing Malpighian tubes differ from the rest by being 
