1895.] Entomology. 67 
the imago state the great majority of insects have their simple eyes in 
addition to the compound eyes. In many cases, however, the former 
are more or less covered with vestiture, which is another evidence that 
their function is of a low order, and lends weight to the view that they 
are useful chiefly for near vision and in dark places. The compound 
eyes are prominent and adjustable in proportion as they are of service 
to the species, as witness those of the common house-fly and of the 
Libellulide or dragon flies. It is obvious from the structure of these 
compound eyes that impressions through them must be very different 
from those received through our own, and, in point of fact, the late 
experimental researches of Hickson, Plateau, Tocke and Lemmer- 
mann, Pankrath, Exner and Viallanes, practically established the fact, 
that while insects are shortsighted and perceive stationary objects im- 
perfectly, yet their compound eyes are better fitted than the vertebrate 
eye for apprehending objects set in relief or in motion, and are like- 
wise keenly sensitive to color. 
So far as experiments have gone isa show that insects have a keen 
color sense, though here again their sensations of color are different 
from those produced upon us. Thus, as Lubbock has shown, ants are 
very sensitive to the ultra violet rays of the spectrum, which we can- 
not perceive, though he was led to conclude that to the ant the general 
aspect of nature is presented in an aspect very different from that in 
which it appears to us. In reference to bees, the experiments of the 
same author prove clearly that they have this sense of color highly 
developed, as indeed might be expected when we consider the part 
they have played in the development of flowers. While these experi- 
ments seem to show that blue is the bee’s favorite color, this does not 
accord with Albert Miiller’s experience in nature, nor with the general 
experience of apiarians, who, if asked, would very generally agree 
that bees show a preference for white flowers.” 
Origin of Reproductive Cells in Insects.—J. W. Tutt dis- 
cussing the life history of a lepidopterous insect says of this subject :° 
“The earliest development of the ovum and spermatozoon in the 
embryo of insects is very obscure, but it would appear that the primi- 
tive ovaries are composed of a mass of cells, produced by an infolding 
of the ectoderm; but whilst some writers assert that they arise from 
the ectoderm, others consider them to be derived from the mesoderm, 
whilst still others trace their origin back to certain so-called pole cells, 
which originate even before the blastoderm is formed. However, this 
3 Entomologists Record, V, 246. 
