1920.] 
Natural-history Notes. 
57 
of certain other insects, comparing his own results with those of many 
other observers. The consensus of opinion drawn from these investigations 
appears to be that the picture on the retina of the butterfly’s eye is a mosaic. 
In addition to figures of anatomical details, a coloured plate is given show¬ 
ing a tortoiseshell butterfly (1) as it appears to the human eye, (2) as it is 
assumed to appear to another of the same species at a distance of 2 in., 
and (3) the same on the same assumption at a distance of 12 in. The last- 
named figure (3) is a very indistinct image, and is about the limit of recog¬ 
nizable visibility ; the author, however, from his own special investigations, 
considers that the distance at which recognition can take place should be 
extended to 3 ft. A great number of experiments were carried out with 
butterflies in the field, particularly in connection with the power of the 
living insect to recognize individuals of its own species. Cabinet specimens 
were used, which were scented with museum preservatives, thus eliminating 
the possibilities of recognition by scent. Tables are given showing how 
many times butterflies recognized specimens of their own species as against 
specimens which had been specially painted, and the evidence in favour 
of the recognition of the natural insect is overwhelming. Experiments were 
also made in order to determine the kind of flowers more frequently visited 
by butterflies, and it was found that these were precisely those kinds most 
conspicuous to human eyes. Photographic experiments were also made to 
determine those flowers having the greatest luminosity. These were not 
the same as those most conspicuous to human eyes, and the amount of 
relative luminosity thus determined did not influence the butterfly, which 
always selected the most conspicuous, and the kind which experience indi¬ 
cated had the richest store of honey. After reading Dr. Eltringham’s paper 
it is, I think, abundantly clear that butterflies see colours much the same as 
human beings do, and the contention of colour-blindness brought forward 
by the German physiologist Hess is shown to have no 'actual foundation 
in fact. 
Article 3, by Mr. C. B. Williams, gives a series of accurate observations 
on a migration of yellow butterflies (Catopsilia statira ) in Trinidad. The 
migration lasted, with certain intervals, from the beginning of September 
until the 12th October, and in some places the butterflies were in such pro¬ 
digious numbers that it was impossible to drive a motor-car while the flight 
was proceeding. Mr. Williams further states that where the butterflies 
were resting on the ground the appearance from a distance was that of large 
patches of yellow-green grass. To those who have never visited the tropics 
such a profusion of butterflies as that described by Mr. Williams seems 
almost incredible. 
Article 5, by G. Chester Crampton, treats at some length of the ancestry 
of insects, and covers much of the ground recently traversed by Dr. Tillyard 
in his articles entitled “ The Panorpoid Complex,” now being issued through 
the Linnean Society of New South Wales. These authors substantially 
agree with the views set out by the older entomologists that the order 
Neuroptera, in the broad sense, includes the most primitive insects now 
living. They, however, divide the old order Neuroptera into a variable 
number of new orders, mostly agreeing with the old families, which comprise 
dragon-flies, alder-flies, lacewing-flies, &c., to which they have given new 
names ; and, as the original family designations are not given in brackets, 
as in my opinion they should be, many will find considerable difficulty in 
following the arguments advanced in both the papers referred to. 
At the meeting of the Entomological Society held on the 19th March last 
Dr. Eltringham exhibited a specimen of the pupa and imago of Cryptophaga 
rubescens, a tineid moth whose larva burrows in stems of acacia in Queens¬ 
land. When the larva is about to pupate it takes up a position close to the 
