KOLLIKER, ON LAMPYRIS. 167 
gonal form, and from 0:01” to 0°02” in size. With respect 
to their contents, they may be divided into two groups,— 
the pale and the ‘white, between which, however, transitional 
forms may be observed. The former, or pale cells, contain 
pale, delicate granules, and in them may be perceived a 
minute, rounded nucleus; whilst the latter, or white cells, 
are so densely filled with white, spherical, minute eranules, 
having an oily aspect when viewed by transmitted light, that 
no other constituent can be seen in them. 
The disposition of these cells is such, that in the ventral 
luminous organs of the female of both species, and of the 
male in L. splendidula, the outer portion contiguous to the 
chitinous integument consists of the pale cells, whilst the 
inner or deeper part is constituted of the white. No very 
definite line of demarcation, however, can be drawn between 
the two. In the lateral, more detached, organs of the female 
L. splendidula, and in the luminous organs of the male of 
L. noctiluca the white cells occupy the entire surface. Al- 
though, as it appears to me, in the former the dorsal, and in 
the latter the ventral, aspect of the organs is less thickly 
covered with them. In certain cases, also, the white cells 
may be wholly wanting, or are represented by bodies con- 
taining only a few white granules. 
6. The numerous trachee enter from the upper, or, in the 
lateral organs, from the inner, side, forming the most abund- 
ant and elegant ramifications among the pale cells. The 
finest twigs of these vessels which appear to form loops were 
visible everywhere among the pale cells; but im the ventral 
organs they are the most numerous on that surface of the 
organ which is turned towards the external world, whilst in 
the others they exist all over the superficies. The chitinous 
integument of the larger tracheal trunks supplying these 
organs supports, as elsewhere in Lampyris, fine hairs. 
7. The nerves, which were not found except after prolonged 
and troublesome resear ch, enter the organs in company with 
the trachez and ramify among the pale cells, though by no 
means so abundantly as the trachez. They are of a pale 
aspect, here and there furnished with nuclei, and at the 
points of division also with nucleated enlargements, from 
which two to five branches are given off. The resemblance 
between the pale cells of the parenchyma and nerve-cells, 
suggested the possibility of some connection between the 
former and the nerves, but hitherto I have not succeeded 
in observing anything confirmatory of this supposition. 
The ultimate termination of the nerves, also, remained 
altogether in the dark. 
