PHYSIOLOGY OF THE INVERTEBRATA. 155 



When the blood is treated with alcohol and potassium 

 hydroxide and filtered, a yellow-coloured solution is obtained 

 " free from bands, but on adding ammonium sulphide a band 

 appears covering D " (Fig. 30, d^. " On treating aqueous 

 solutions with acetic acid the bands faded away, and the 

 colour of the solution changed to a brownish colour (gaslight)." 



MacMunn tried the action of alcohol acidulated with 

 sulphuric acid on chlorocruorin, and obtained a greenish 

 solution, which showed a faint shading in the green, too 

 indistinct to map. 



" Hence none of the decomposition products of hsemoglobin 

 or hsematin could be obtained, the pigment, as Prof. Lan- 

 kester had already shown, being destroyed by the reagents 

 required to produce acid hsematin and hsematoporphyrin. 

 The blood of the pseudo-hsemal system of Serpula contortu- 

 pliccda presents some resemblance to that of Sabella. There are 

 slight differences in the blood spectra of some specimens, which 

 doubtless are due to the pigment being present in different 

 states of oxidation, and on comparing some of these spectra 

 with those of the histoheematins and with the decomposition 

 products of haemoglobin, a striking likeness is apparent." 



" On putting a Se'rpula into the compressorium, and bring- 

 ing gentle pressure to bear on the upper surface of the 

 animal, and examining with the microspectroscope, using a 

 good achromatic substago condenser, a series of spectra are 

 obtained when the various pai-ts of the animal are moved 

 under the objective ; what these parts are is seen by looking 

 down the left-hand tjabe of the microscope. In this way we 

 can differentiate the blood-vessels, intestine, gills, opercu- 

 lum, and other parts, and study the spectrum of each." 



With the pseudo- haemal system of Seij>ula, MacMunn 

 obtained a spectrum represented in Fig. 30, e. The band 

 before D is like that of Lankester's chlorocruorin, but the 

 first after D and also the second are different. 



An aqueous solution of the blood from the pseudo-haemal 

 system is yellow by daylight, reddish- yellow by gaslight, and 



