Entomology. 939 
(f£) The antenne are much used in testing the path and surround- 
ing objects. | 
(2) In the next chapter Prof. Plateau discusses the function of 
the frontal ocelli of adult insects. He gives an historical summary 
of past researches, describes the manifold conditions of his own 
observations and experiments, submits tabulated results of his 
investigations of different forms, and formulates the following con- 
clusions: (a) Diurnal winged insects, Hymenoptera, Diptera and 
Lepidoptera, when blinded by covering the entire eyes with black 
or by cutting all of the optic nerves, rise to a great height in the 
air when liberated. (b) When the compound eyes are suppressed, 
but the frontal ocelli left, in Hymenoptera, Odonata, and Diptera, 
the insects behave exactly as if the ocelli also had been suppressed. 
When freed, they rise vertically as before. In a chamber lighted 
from one side they behave as if they were totally blind. (c) But 
if the frontal ocelli be alone suppressed, the above insects hehave as 
if they had lost nothing. (d) In diurnal insects equipped with 
compound eyes the ocelli count for almost nothing. They only 
afford the animals very feeble perceptions which they do not know 
how to. use. 
The author concludes his memoir with the following suggestions, 
which he describes as “ plausible hypotheses,” supported by a cer- 
tain number of observed facts: (1) Diurnal insects, in which all 
of the eyes have been suppressed, still enjoy dermotoptic perceptions. 
(2) They are almost reduced to the same limitations if the ocelli 
are left at their disposal. (3) The dermotoptic perceptions are the 
primary cause of the ascending flight of liberated blinded insects. 
(4) The frontal ocelli serve neither for the perception of movements 
in adjacent objects, nor for the perception of light in relative obscure 
media. (5) The simple eyes, which the author has shown to func- 
tion in an imperfect fashion in most Myriapods, in many Arachnids, 
and caterpillars, have entirely lost their utility in the great majority 
of insects equipped with compound eyes. (Jour. Roy. Mier. Soc., 
June, 1888.) 
Lire or TOWNEND Guover.—A biographical sketch and an 
account of the writings of the late Towend Glover, the first United 
States Entomologist, written by Mr. Charles R. Dodge, has just 
been published by the Department of Agriculture at Washington.? 
Mr. Dodge was for a long time the assistant of Mr. Glover, and 
was one of his most intimate friends during the wis, "aes of his 
life. He is, therefore, well fitted to ney Pas this office and has 
done it in a very satisfactory manner. The work is illustrated by a 
portrait of Mr. Glover, copies of two of his earlier plates, and by 
several of his humorous caricatures. Numerous anecdotes are given 
1 U. S. Dep. of Agri., Div. of Ent., Bull. No. 18. 
