PHYSIOLOGY OF THE INVERTEBRATA. 8i 



of Vddla and Porpita, as described by Voigt. Subsequently 

 Haeckel found starch in these cells, and concluded that this 

 feet supported the idea of the nutritional function previously 

 Assigned to them by himself.* 



" Oienkowskif in 187 1 endeavoured to show that the yellow- 

 cells of Radiolarians were iparasitic algae, since they survived 

 the death of their host, and multiplied subsequently, passing 

 through an amoeboid and encysted state." 



There is no doubt that the " yellow cells " do survive for 

 some time in the bodies of dead Eadiolarians ; but in regard 

 to Hydra and Spongilla, Prof. E. Ray Lankester| has shown 

 that " the chlorophyll corpuscles of these animals are not alg£e 

 at aU (as stated by Dr. Brandt §), but differ in no essential 

 respect from the chlorophyll bodies of plants." 



Dr. C. A. MacMunn|| has shown that "the chlorophyll 

 bodies of SpoTigilla, Hydra, Faramcecium, Ophrydiuvi, Vortex 

 iriridis, and Stentor polymorphus are of different size, colour, 

 and give different reactions, and a different spectrum, from 

 the ' yellow cells ' of Actiniae. With regard to size, the 

 ' yellow cells ' of Anthea cereiis were found to measure I2fi 

 (= 12x3-^^ mm.), or i^iJ. down to lOyu; while in Fara- 

 Viioecium they measured from 6fi down to 3ju — i.e., less than 

 half the size of the former ; in Hydra viridis mostly from 

 Sfi to 4fx. The colour is a dull brownish-yellow in the 

 ^ yellow cells ' of Anthea, &c. ; while it is a fine green in the 

 Infusoria and Hydra. The spectrum in Spongilla, in Hydra, 

 and in the Infiisoria is that of plant chlorophyll ; while in 

 the ' yellow cells ' it is that of chlorofucin." 



The chief function of animal chlorophyll and allied pig- 

 ments is that of respiration; but it is probable that these 

 pigments play an important part in sexual selection, in 



* Jena Zeitsch. 1870, p. 532. 3 

 ■t Archiv. Mihro. Anai. 1871. 



X Quarterly Journal of Microscopical Science, vol. 22, p. 229. 

 § Monatsb. Ahad. Wiss. Berlin, 1881. 



Jl Proceedings of Birmingham Philosophical Society, vol. 5, pt. i, p. 212. 



F 



