Life History of Tetropium gabrieli. 205 
(3) Several 22 and $2, var. d, selected and treated the 
same way, May 13th, 1906, produced between August 10th 
and September 6th, 1906, 123 imagines, ail of var. b, except 
two individuals in which the reddish tinge in the femora 
was so obscure as to be hardly perceptible. 
(4) A similar experiment in another log produced 60 
individuals of var. D. 
(5) I have besides reared three successive generations 
from var. b stock, each numbering about 200 individuals, 
without a single instance of the type form occurring, and 
only one or two at most in each generation in which the 
reddish tinge in femora was so obscure as to be hardly 
perceptible. 
(6) I have reared hundreds of other imagos from 
var. 6 stock taken from different localities with the same 
result. I conjecture from this that the type form (with 
red femora), is not likely to be produced from var. ) stock 
(with black femora) in Larix europea. And yet, as I 
have shown above, the most intense black form was in two 
different experiments produced from the brightest red 
parents. No instance of the fulvous-ferruginous elytra, 
visible in varieties of 7. fuscwum and T. lwridwm, have 
occurred in 7’. gabrielt in my experience, as might have 
been expected. 
(7) From my single log of Picea excelsa, on which ova 
were deposited by var. 6 stock June 1906, I reared about 
15 imagos of the var. 0. 
(8) From my single log of Pinus laricio, var. nigricans, 
oviposited on by var. b stock March 1906, I reared only one 
imago, and that of the var. form. Unfortunately the rest 
of the larvee perished in forcing over gas. From these latter 
food-plants I had rather anticipated obtaining, in some 
degree at least, the fulvous-ferruginous elytra of 7. 
fuscum and 7, luridum, or the pitchy red of Asemwm 
striatum, var. agreste. 
(3) STRUCTURAL AND ScuLprurAL VarRtiaTion.—Marked. Mul- 
sant’s description of Cerambyx luridus, L. (= T. lwridwm, L.), in 
respect of this applies in every detail to T. gabrieli :— 
“Le prothorax offre des différences sensibles sous le rapport de 
son développement en longeur et en largeur; de sa forme; de son 
rétrécissement plus ou moins sensible dans sa seconde moitié ; de 
la profondeur de son sillon; de sa ponctuation. L’écusson est 
ordinairement canaliculé; d’autres fois il le pairait a peine. Les 
nervures des élytres sont plus ou moins prononcées.” 
