296 
Hab. Fresh water. River Breamish, Ingram; river Coquet, 
Elyhaugh, frequent. According to Rabenhorst this species 
is generally distributed through Germany, Belgium, France, 
Switzerland, and Italy. 
Note on a New Means of examining Blood under the 
Microscope, and on the Blood-Fluids o/Tnvertebratks, 
and on a Natural Standard for registering Absorp- 
tion Spectra. By E. Ray Lankester, B.A., Ch. Ch. 
Oxon. 
My friend, Dr. Arthur Gamgee, last year suggested to me 
that I should try the new blood-matter, Chlorocruorin, which 
I discovered in Siphonostoma and Sabella two years since 
(see Humphry’s and Turner’s ‘Journal of Anatomy,’ Nov., 
1867) with Day’s guaiacum-and-peroxide-of hydrogen-test 
(see ‘ Quart. Journ. Mic. Sci.,’ 1868, p. 282). This I accord- 
ingly did, and obtained the most satisfactory results, the 
guaiacum being rendered brilliantly blue in the usual way by 
the Chlorocruorin and ozonic ether. I also proceeded to try 
a great number of blood-fluids of Invertebrata. In all cases 
where the presence of Haemoglobin (Cruorin) had been 
proved by me with the spectroscope to be present I did not 
fail to obtain the blueing of the guaiacum, e. g., in Planorbis, 
in larva of Chironomus and allied larvae, and many Annelids. 
The colourless fluids among these groups I also tested with 
the guaiacum and “ ozonized ether,” having been led to sus- 
pect that in the colourless blood of insects, molluscs, &c., 
there must be a body having properties similar to those of 
Haemoglobin and Chlorocruorin. The perivisceral fluid of 
Annelids gave the blue colour with guaiacum, the colourless 
blood of some insects, Crustacea, and molluscs also. In many 
there was simply an evolution of gas on the addition of the 
ozonized ether, and no blueing of the guaiacum. I attribute 
this to the fact that the action was less energetic in these 
cases than in the case of the red Haemoglobin or cruorin, 
which acts far more powerfully with the test than anything 
else, excepting Chlorocruorin. The mere evolution of the 
gas is, however, a good test, and can be applied beneath 
the microscope. Thus, I have been able to bring ozonized 
ether into contact with very small Entomostraca, and 
even with some Infusoria, on the microscope-stage, and 
