PROGRESS OF MICROSCOPICAL SCIENCE. 93 
we study in the fresh condition the bdtons of various species—of 
the crayfish, for instance—and placing them in a drop of the liquid 
serum of the body, we very soon find that the brownish colour which 
is usually attributed to them belongs to the pigmentary cells with 
which they had been surrounded; their colour is absolutely of a very 
elegant roseate hue. And this observation is completed by the 
following: on the surface of each bdton may be seen lines which 
appear to divide it into equal segments, and, prepared in the manner 
described above, it may be seen that it separates into discoidal 
lamelle. The author records the same facts as having been observed 
by M. Schultze in his researches on Batrachians and Fish, but there 
must be no homology between the eyes of fish and crustacea. Neither 
can we [ Ep.‘ M. M. J.’] conclude with M. Chatin that there is no trace 
of muscular tissue in either the eyes of crustacea or fishes, though of 
course we admit the former part of the statement. 
The cone, which corresponds to the crystalline lens of various 
writers, seems to be of a variable appearance (ovoid, prismatic, or 
club-shaped), and presents a characteristically refractive power. At 
its upper part may be seen the cells of Semper, the importance 
of which Claparéde has shown. In some cases one may see towards 
the central region a line which has been styled the “ filament of 
Ritter.” He thinks that the axile line of the cone should be gene- 
rally regarded as indicating the plane of intersection of pieces 
originally distinct. The author thus classifies the Crustacea in ac- 
cordance with the development of the eye: Astacus, Homarus, Squilla, 
Eupagurus, Pagurus, Paguristes, &c., possess batons of a decidedly 
superior form, and also may be added Cypridina. But in Typton 
Lysianassa and Iscea one observes a manifest simplicity in the batons, 
which is still more evident in Notopterophorus and Caprella. It 
shows itself more completely still in Hpimeria, and, above all, in 
Lichomolgus, where the eye is reduced to a small number of elements 
that show hardly any relation to the foregoing. 
A Contest as to Priority of Discovery—Those who read the 
‘American Naturalist’ will have observed in a recent paper that 
Mr. A. 8. Packard, jun., makes a claim which appears to us so just 
that we have no hesitation in calling attention to it. In a review 
of Dr. Paul Mayer’s recent essay on the “Ontogeny and Phylogeny 
of Insects,” Mr. Packard very ably attacks the German writer. He 
Says : 
“ ‘Ontogeny’ is a term devised by Haeckel, and means the 
development or embryonic and post-embryonic changes of the indi- 
vidual; ‘phylogeny’ corresponds to its English equivalent, ‘an- 
cestry, while the present essay is an attempt to explain the origin 
and ancestry of the six-footed insects (Hexapoda) from embryological 
and anatomical data. No new facts, as far as we are aware, are pre- 
sented by the author, whose essay has, apparently, contrary to usage 
in German universities, been crowned not for the original work it 
contains, but for the ideas suggested by the labours of preceding 
authors. 
“ In trying to reconstruct the form of the primitive insect, Mayer 
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