124 Proceedings of Royal Society of Edinhurgh. [sess. 
pigment appears to be present in the blood of the Lepidoptera. 
The existence of a respiratory pigment is doubtful, especially when 
one bears in mind the anatomical disposition of the respiratory 
apparatus in these animals, the penetration of the air by the 
tracheae through all the living tissues. Nevertheless, the blood of 
the Lepidoptera is rich in proteids, and it is capable of abstracting 
and retaining a considerable amount of oxygen. The author has 
ascertained the percentages of saline matter contained in the blood 
of the larvae of certain Lepidopterous insects, &c. These per- 
centages are as follows : — 
I. 
II. 
III. 
Average. 
^Pontia hrassicce, .... 
1 ^ Noctua pronuha, 
^ 1 Vanessa io, .... 
^ Smerinthus tilice, 
^ 1 1 Lucanus cervus, .... 
o -p i 
^ o' 1 Dytiscus dimidiatus, . 
3-62 
3-84 
3-91 
3-92 
3-51 
3-48 
3-71 
3*77 
3-98 
3-99 
3-49 
3-50 
3-68 
3- 81 
4- 00 
3-87 
3T.5 
3-46 
3-67 
3-80 
3-96 
3-92 
3-51 
3-48 
The blood was obtained from a large number of individuals in 
each case. 
The [ashes of the blood of these insects yielded the following 
results * : — 
Pontia 
hrassicce. 
|i 
n 
Vanessa io. 
Smerinthus 
tilim. 
cc 
e 
^ 5- 
S 
s 
CO 
s 
§1 
Iron oxide (Fe20g), 
010 
0-09 
0-11 
0-09 
0-10 
0-08 
Lime (CaO), . 
2-02 
2-96 
2-06 
2-43 
2-25 
2-21 
Magilesia (MgO), . 
1-00 
1-12 
1-09 
113 
1-16 
1-09 
Potash (KoO), 
412 
4-09 
4-06 
4-10 
4-20 
417 
Soda (Na^O), 
43-48 
44-03 
43-62 
43-29 
44-00 
43 -62. 
Phosphoric acid (P20g), . 
3-21 
3-61 
3-50 
3-40 
3-32 
3-41 
Sulphuric acid (SOg), 
2-91 
2-80 
2-87 
2-92 
2-83 
2-80 
Chlorine, 
43-16 
41-30 
42-69 
42-64 
42-14 
42 -62 
100-00 
100-00 
100-00 
100-00 
100-00 
100-00 
The averages of two analyses in each case. 
