962 The American Naturalist. [November, 
there are in its embryo four distinct cephalic segments, which, in the 
early stages of embryonic development are large (compared with the 
other segments which are developed later), and are made still more 
distinct by the possession of buds or processes. As development goes 
on, these four segments get welded together, and become not only pro- 
portionately, but absolutely smaller than at first. When the abdominal 
segments are in course of development, there certainly appear to be 
eleven of them. The three thoracic segments are, in the early stages 
of development, large and almost circular, and the next segment (1st 
abdominal) is of the same character, looking at this time much more 
like a thoracic than an abdominal segment, though it has, of course, no 
appendages. The eye spots in this species are remarkably conspicuous 
as two reddish patches, and become apparent at about the same time 
that the abdominal segments first show. As development proceeds, 
the cells of the developing 7. ferrugana appear to be stained here and 
there with red patches, especially along the ventral area of the alimen- 
tary canal, but differently distributed in different examples. These 
afterward spread over the whole of the embryo.” It was suggested 
that this color was connected with the skin. The. thoracic legs de- 
velop when the embryo begins to show segmentation. The embryo is 
then somewhat curved, ** with the head slightly bent round toward the 
anal extremity, but with the legs outside, i. e., the larva is bent back 
upon itself so as to form a curve agreeing roughly with the curvature 
of the shell, with what afterwards becomes the ventral surface of the 
larva outside and the dorsum towards the centre. The embryo then 
gradually changes its position, the anal segments curling around and 
being pushed by the growth of the preceding abdominal segments 
slowly up the ventral surface of the larva whilst the dorsum gets 
pushed out, as it were, towards the centre of theegg. During this pro- 
cess the embryo becomes shaped something like the letter S, the move- 
ment continuing until a complete reversal of the embryo has been 
affected 
The Rabbit Bot Fly—Cuterebra cuniculi Clark.—We are 
greatly indebted to Mr. Percy Selous, of Greenville, Mich., for speci- 
mens, notes and drawings of the rabbit bot fly, Cuterebra cuniculi. 
The larva of this species is quite often taken from the rabbit, though 
few persons are successful in rearing the fly from the larva, and Mr. 
Selous is to be congratulated on his success. 
The notes of Mr. Selous on the rearing of the bot are as follows: 
‘The ripe larva dropped from a rabbit I shot last September. The 
