TYPES IN NATURAL HISTORY. 313 



I am not quite sure that all breeders of lepidoptera will agree with 

 Mr. Tutt that the conditions of confinement are usually such, that the 

 males will more easily survive, when broods are reared in captivity, 

 than the females. I have very little experience myself on any large 

 scale, but I had an impression that the females more readily defied the 

 unnatural conditions imposed by captivity than the males. This would 

 be a point on which the experience of some of those observers who now 

 rear large numbers of species would be valuable, not merely their 

 statistics, but their impressions of what befel the two sexes in cases 

 where the imagines resulting were only a final remains, after losses of 

 their breth^-en throughout the whole life of a brood. 



Another point that struck me as curious was this. The excess of 

 males over females bred by Standfuss, was, in the mass, very definite, 

 and may perhaps be taken, from its averaging so many and varied 

 experiences, to be not far from a real measure of the relative numbers 

 of the two sexes in lepidoptera. This excess of about 5% is of quite a 

 different order from the oO%, 500%, or 5000%, the absurdity of which 

 Mr. Tutt points out, but is not only of the same order, but not very 

 far from the same amount, as that of the excess of male over female 

 births in the human species in these islands. It is a inatter of specu- 

 lation, at present, as to whether this correspondence has or has not 

 some real common cause in both instances, for any really valuable 

 conclusion on the matter further research is no doubt needed. The 

 only common condition that unquestionably obtains in both instances, 

 is that usually of the two parents the male is generally the older. But 

 in the present position of our knowledge, to advance any such theory 

 is much the same kind of philosophy as that of which Mr. Tutt's article 

 exposes the absurdity. 



Types in Natural History. 



By LOUIS B. PROUT, F.E.S. 

 I am glad that my note has called forth Mr. Wheeler's ably- written 

 article. I now understand his position, and apologise for insufficiently 

 studying his lucid introduction, p. 3 ; he has only " not defined it " in 

 the sense that his starting point is illusory — unpractical, as he almost 

 admits himself; unscientific, as assuming the objective existence of 

 natural " types." Mr. Wheeler believes in " distribution" types ; Mr. 

 Kaye tells us that the " man in the street " believes in " average 

 types " ; Dr. Chapman (m litt.) told me that all my four meanings are 

 "species" in one "genus"; Mr. Kaye tells us that they are tiro 

 genera ; all of which is very illuminative. As I have already said, 

 increasing knowledge will constantly modify our conceptions of nu- 

 merical preponderance, whether of individuals of a form, or of locali- 

 ties producmg a form. Mr. Wheeler has the courage of his opinions, 

 for which I admire him, but I feel convinced the excellent work be is 

 doing will compel him to modify them before he has " inundated us 

 with many further changes." What is the "distribution type" of 

 ar;ins, Linn., or of tiphon, Rott. ? What of secalin, Linn., or of 

 hicoloria, Vill. ? In my own special work I have come across many 

 cases where there seem to be Mr. Wheeler's "miracle of ill-luck and 

 monument of premature definition." Working chiefly among butter- 

 flies whose head-quarters are in Europe (where entomologists, too, 

 have theirs), he has not appreciated the probabilities of trouble ; scores 



