DR, F. LEUTHNER ON THE ODONTOLABINI, 395 
arrived at very interesting results, which I will reserve for future publication, as they 
are rather beyond the limits of the present investigation. 
The table opposite will show how difficult it is to decide such questions with 
insufficient material, how differently various authors have attempted to do so at 
different times, and how different species have been alternately separated and united 
from the time of Hope and Burmeister to the present day, 
(4) Odontolabis alces, Faby. (a morphological study). 
Among the above-mentioned species Odontolabis alces deserves special study, as it 
is extremely interesting both from a historical and from a morphological point of 
view ; and on account of the great mass of material at my disposal, which enabled me 
to study it more fully than any other species. 
(a) Evidence of the Specific Identity of O. dux, Westw., O. alces, Fabr., and 
O. cumingi, Hope. 
Through the kindness of Herr G, Schneider, of Basel, I have been enabled to 
examine 223 specimens of this Stag-Beetle, which is generally known as O. dua, Westw. 
They were received from Manilla, and 112 specimens were males and 111 females. 
The females varied in length from 59-52 millim., and the males from 45-99 millim., 
inclusive of the mandibles. 
When I first examined the whole series, I was immediately struck with the great 
similarity of the females (Pl. LXXXIX. fig. 8), while the males appeared in four 
distinct forms (Pl. LXX XIX. figs. 1, 3, 5, 6), which nevertheless all seemed to belong 
to the same species, as they were connected together by transitional forms. ‘This cir- 
cumstance, and the large amount of material before me, naturally led me to make 
further investigations, as I had long been anxious to meet with such a series, in order 
to study the laws and limits of variability between individuals belonging to one and the 
same species. In this case no doubt could exist respecting the correct identification of 
the sexes, as they were all from the same locality. 
It was only necessary, in the first instance, to ascertain whether the females all 
belonged to the same species. If so, there could be no doubt that the males would prove 
to do so also. But I went another way to work, and verified this point at a later time, 
when IJ had learned to distinguish between the females of a considerable number of 
species of Lucanide, which, owing to their great resemblance, is a most difficult task. 
T also convinced myself by careful examination that the smallest males (Pl. LX X XIX. 
fig. 7), although so similar to the females, possessed fully developed sexual organs, 
and were not to be regarded as sexually imperfect individuals, as some authors haye 
suggested. By a careful selection I was enabled to pick out an almost uninterrupted 
series of transitional forms from the largest to the smallest males. 
3Nn2 
