PHYSIOLOGY OF THE INVERTEBRATA. 169 



stcLgnalis, Helix poviatia, and Helix aspersa ; and in all these 

 he observed that the blood became blue by shaking with air 

 and oxygen, and that the blue colour disappeared in the 

 presence of carbonic anhydride. Krukenberg states that in 

 the blood of the three last-named Molluscs there exists a 

 body very nearly related to, but different from, haemocyanin ; 

 but there is no doubt that hsemocyanin exists in the blood of 

 these animals. 



Krukenberg could find no haemocyanin in the blood 

 of Tetliys fimbria, Boris tuierculaia, Aplysia depilans, and 

 Fleurobranchus. 



Many years ago the blood of Aiiodonta cygnea was 

 examined by Schmidt,* who described it as colourless ; but 

 the blood of this Lamellibranch contains, without doubt, 

 hsemocyanin. 



Among the Mollusca, MacMunnf has examined the blood 

 of Helix pomatia, Helix aspersa, Faludina vivipera, and 

 Zimnceus stagnalis. The blood of these animals gave no 

 absoqDtion bands when examined by the microspectroscope. 



" The blood of Helix aspersa was found to be a bluish- white 

 colour by daylight, but by gaslight it had a purplish tinge ; 

 after twenty-four hours' standing that had disappeared, and 

 it was then very slighly brownish. Examined in a deep 

 layer, no bands could be seen ; on treatment with ammonia, 

 the blue colour persisted, and no bands catne into view. 

 With acetic acid the blue colour persisted, and no bands 

 . appeared. After repeated filtering the blue colour remained ; 

 hence it can hardly have been due to particles in suspension. 

 On treatment with reducing agents the blue colour was lost, 

 and no bands appeared." 



The blood of Helix pomatia " assumed a distinct blue 

 tinge on exposure to air, and gave no absorption bands, but 

 absorbed a little of the violet end of the spectrum. On 

 treatment with ammonia its colour was not so well marked, 



* Lehmann's Handbzich der Physiohgischen Chemie. 

 t Quarterly Journal of Microscopical licienee, 1885. 



