ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
533 
specialisation by reduction. This may take place by atrophy of veins, 
or by a coalescence of two or more adjacent veins. In this connection 
they describe the venation of the wings of certain Plecoptera, of Psocus , 
of a Cicada , of Heteroptera, Lepidoptera, Trichoptera, and Diptera. 
Daily and Seasonal Activity of Hive-Bees.* — Mr. F. C. Keny<5n 
gives an account of a series of experiments made by a French bee- 
keeper, M. Leon Dufour. By hourly recording the weight of a hive, the 
experimenter obtained data from which it was possible to plot daily and 
seasonal curves showing the relations between the activity of the bees and 
the flow of nectar during the day and the season, as well as the relation 
between the daily amount of nectar collected and the number of bees 
in the hive, and between the number of bees and the different seasons. 
The curves showed that, at any rate in the locality where the experiments 
were made (Fontainebleau), there are four distinct periods of honey-flow, 
two comparatively poor and two abundant. These latter are due to the 
blooming of acacias and heather respectively. During the poor flow 
there is a period of comparative inactivity in the middle of the day, 
corresponding apparently to a period of small flow of nectar. During 
the season of abundant flow, the activity of the bees is more or less 
constant throughout the day. Apart from such midday inactivity, the 
bees go and come steadily, and the hive, after the minimum is passed, 
increases in weight progressively and with comparative steadiness. 
When the flow of nectar is poor, the bees leave the hive slowly for 
the first hour or so ; then the rate of departure is rapid till the minimum 
Weight is reached. When the flow is abundant, the reduction in weight 
is less marked, probably because the bees secure their stores easily and 
return more frequently to the hive. 
Early in May the workers were numerous, and their numbers in- 
creased rapidly up to the middle of July, but fell again until, in the end 
of August, comparatively few left the hive. 
Geographical Distribution of Ants.j — Dr. 0. Stoll directs attention 
to some of the new facts which have been established in regard to the 
geographical distribution of ants. Perhaps the most important result 
is the evidence of a striking relationship between the ant-fauna in the 
tropical and sub-tropical parts of Australia and that in India and the 
Indian Archipelago. New Guinea is an important connecting link 
between the two. 
Psychical dualities of Ants and Bees.J — Herr A. Bethe credits 
an animal with “ psychical qualities ” when it gives evidence of utilising 
its experience and of controlling its action in relation to what it has 
learned. Without this, it is only a Peflexmaschine , exhibiting reflexes, 
the more complex of which are usually called “ instincts,” though the 
author avoids the word. As to the origin of these reflexes, he agrees 
with Weismann and not with Wundt. 
Among his experiments are the following : — If a Myrmica or Cam - 
ponotus herculeanus be washed and then bathed in the juice of Tetra - 
* Amer. Nat , xxxii. (1898) pp. 90-5. 
f MT. Schweiz. Ent. Ges., x. (1898) pp. 120-6. 
X Arch. Ges. Physiol., lxx. (1898) pp. 15-100 (2 pis.), See Zool. Centralbl., v. 
(1898) pp. 273-6. 
2 O 2 
