58 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
life, the year’s work, and the manner of death. We must, however, 
simply refer to the original memoir. 
Statistics of Wasps.* — Prof. F. G. Edgeworth, the well-known 
political economist, points out that the number of wasps in a nest may 
be inferred from the number issuing per minute if (1) we know the 
average time occupied by a wasp in the cycle of operations between two 
successive exits ; (2) we assume that the whole population is occupied 
in keeping up the traffic. The author has collected some statistics 
bearing on the first datum. The average time occupied by the wasps 
which he has observed in loading is six minutes. The average interval 
between the departure of a laden wasp and the return of the same wasp 
for another load is nine minutes. Accordingly the mean periodic time 
for a wasp employed in collecting sweets may be assumed to be about 
15 minutes. The corrected figure is 20. If the number of wasps issuing 
per minute is x , the total number would be 20 multiplied by x, if 
assumption 2 is true, but how inadequate it is, is shown from the fact 
that the same nest within a short period shows very different rates of 
traffic. Thus a nest which at the beginning of a week had a traffic 
of 20 per minute, had after three days a traffic of 60 per minute, and 
after two more days a traffic of only 12 per minute. In some cases 
examined by the author the calculated minimum was found to be very 
much below the actual number. 
The Genus Dorylus.f — Prof. C. Emery begins a somewhat hetero- 
geneous paper with an account of the male copulatory organs of ants. 
He gives a useful comparative table of the manifold terminology. The 
terms he himself uses are — lamina annularis, paramera externa (including 
stipites, volsellae, laciniae, squamulae), paramera interna, lamina sub- 
genitalis, and cerci. 
Then he submits a revision of the genus Dorylus , which he divides 
into seven subgenera — Anomma, Dorylus sensu stricto, Typhlopone, 
Dichthadia , Alaopone , Dhogmus, and Shuchardia. A number of new 
species are described. 
Emery divides the family Formicidae into five subfamilies, Dorylini, 
Ponerini, Myrmicini, Dolichoderini, and Camponotini, which he sub- 
divides into tribes. He regards the Dorylini as the first offshoot from 
the original stock, and the Ponerini as the root from which the other 
three subfamilies have sprung. The ancestors of ants were probably 
nearly related to the older forms of Mutilidae, and probably formed small 
societies of wingless females among which sterile individuals afterwards 
differentiated. 
Antennae of Diptera.J — Dr. B. Wandolleck has made some beautiful 
photographs of these, which show the superficiality of the figures 
frequently given. He finds that the forms of antennae do not afford a 
trustworthy basis for classifying into groups or orders, though they are 
of great importance in the diagnoses of genera and species. He proposes 
a phylogenetic arrangement, from simple forms upwards to the complexity 
of Hypoderma and Hippobosca. 
* Rep. Brit. Assoc., 1895, pp. 729 and 30. 
t Zool. Jahrb. Abth. Syst., viii. (1895) pp. 685-778 (4 pis. and 41 figs.). 
t Tom. eit., pp. 779-89 (1 pi.). / 
