Amoeboid eells in intestinal absorptiou. '^O 



in frag-ments of muscle, nerve and tlie rest, and transfer them to tlie 

 body of tlie metamorpliosing' larva, submitting tliem to a sort of intra- 

 cellular digestion on the way. And witli considerable probability 

 the same observer regards many, if not most pathological ab- 

 sorption processes as being effected by a similar agency, tlie 

 white blood - corpnscles appearing to possess the Singular faciilty 

 of seizing and ingesting any foreign substance or dead tissues 

 wliich from disuse or as the result of irritation no longer possess füll 

 vitality; and thus breaking down such foreign substance or tissue and 

 gradually removing it. The fact that milk-globules or vermilion-par- 

 ticles which are injected into the blood-vessels become taken up in 

 great measure by the white corpuscles is a well known instance of thife, 

 tendency, and it is also displayed by their aptitude to ingest bacterial 

 organisms which are introduced into the blood and which it is possible 

 may often in this way be rendered innocuous'). 



But it is not only in processes of internal absorption that amoe- 

 boid cells have been shown to play an active part: they liave also 

 in some animals been proved to be concerned in the absorption and 

 assimüation of food. This has been niost distinctly made out in 

 Sponges, where indeed the Ingestion of particles suspended in the water 

 by the protoplasm of some of the cells lining the canals, was already 

 known to Lieberkühn 2). Metschnikoff'^) as the result of numerous 

 experiments upon the point gives it as his decided opinion that the 

 cells of the mesoderm not only take up food materials but have more 

 or less the power of digesting them as weU. 



V. Lendenfeld^) corroborates this opinion, having found as the 

 result of a careful experimental investigation into the subject, that 

 the amoeboid cells of the mesoderm in Aplysilla not only take up and 

 carry away food -particles wlüch have been absorbed from the sea- 



^) Metscknikoff, Üb. cl. Beziehung- cl. Phagocyten zu Milzbrandbacillen, Virch. 

 Arch. XCVn, 3, 1884. 



'*) Lieberkübn, Beitr. zur Entwicklungsg. d. Spongillen. MüUer's Archiv, 1856. 



3) Metschnikoff, Spongiologische Studien. Zeitschr. f. wissensch. Zoologie, 

 Bd. XXXII, S. 371—374. 



*) E, V. Lendenfeld, Über Coelenterateu der Südsee, II. Zeitschr. f. wiss. Zool. 

 XXXVin, S. 252—254. 



