One feature, however, calls for remark. This second paper is written apparently without any reference to the discoveries related by Tower in his previous book, to which no allusion is made. This is most noticeable in the case of an experiment in which (p. 296, H. 700A) _undecimlineata_ [F] (the dominant) was mated to _signaticollis_ [M] with the result that all the offspring were _undecimlineata_ and bred true to that type (Parthenogenesis was tested for, but never found to occur). This experiment was made at a temperature averaging 95° F. ± 3.5° by day and 89° F. ± 4.8° by night, and in a humidity given as 84 per cent. by day and 100 per cent. by night; but in the previous book (p. 294) we are told that pure _undecimlineata_ bred together "under an extreme stimulus of high temperature, 10° C. above the average" and a relative humidity of 40 per cent. gave 11 beetles only, all _angustovittata_. But reference to the Plate 16, Fig. 2, shows that _angustovittata_ must be exceedingly like _signaticollis_, having, like it, the elytral stripes obsolete, and if there is any marked difference at all, it can only be in the larvae. It seems strange that if _undecimlineata_ really gives off ova of this recessive type at high temperatures, the fact should not be alluded to in connection with expt. H. 700A, where, as the father was _signaticollis_, having the same recessive character, their appearance might have been expected not to pass unobserved. The temperature in the older experiment is, of course, not given with the great accuracy used in the second, and it may have been higher still. The humidity also was widely different. Still, in discussing the phenomena we should expect some reference to the very remarkable and closely cognate discovery which Tower himself had previously reported in regard to the same species.[13] The hesitation which I had come to feel respecting these two publications of Tower's has been, I confess, increased by the appearance of a destructive criticism by Gortner[14] who has examined the parts of Chapter III of Tower's book, in which he discusses at some length the chemistry of the pigments in _Leptinotarsa_ and other animals. As Gortner has shown, this discussion, though offered with every show of confidence, exhibits such elementary ignorance, both of the special subject and of chemistry in general, that it cannot be taken into serious consideration.