INTRODUCTION. 27 



and showed also a nucleus and nucleolus, and a con- 

 tractile vesicle, the latter mostly posterior.* Gradually 

 these bodies settled down. In place of the vigorous 

 amoeboid contractions of the whole body, merely 

 hyaline lobes or finger-like processes were extended ; 

 as they contracted one by one into a globular sub- 

 pyriform figure, a resting-state set in ; then a long 

 vibrating filament was projected from the body, and 

 the metamorphosis of the amoebula into a flagellate 

 spore was complete. The author did not follow their 

 development further. They were not, he considered, 

 in any sense parasitic, but had their origin in the 

 peculiar " shining bodies " (glanzkorper) which occur 

 in large numbers, along with the small nuclei, in the 

 plasma-body of Pelomyxa. These shining bodies are of 

 roundish, ovoid, or irregular figure, and glossy appear- 

 ance. In an individual not very highly charged with 

 extraneous matter they may readily be detected. 



From these remarks it will be seen how diverse are 

 the forms under which reproduction takes place in the 

 simple-celled Rhizopoda. The Heliozoa present no 

 essential difference ; but these will be more con- 

 veniently dealt with under their own proper head. 



It may not be out of place to allude here to the 

 theory of AVeismann and others of the " deathlessness " 

 of the Protozoan cell, thus expounded by Prof. Ray 

 Lankester : f " It results from the constitution of the 

 Protozoan body as a single cell, and its multiplication 

 by fission, that death has no place as a natural re- 

 current phenomenon among these organisms. Among 

 the Enterozoa certain cells are separated from the rest 

 of the constituent units of the body as egg-cells and 

 sperm-cells ; these conjugate and continue to live, 

 whilst the remaining cells, the mere carriers as it were 

 of the immortal reproductive cells, die and disintegrate. 

 There being no carrying cells which surround, feed, 

 and nurse the reproductive cells of Protozoa, but the 



* ' Arch. f. Mikr. Anat.,' x, p. 51. 



f "Protozoa," in ' Encyclopaedia Britannica/ 9th ed. XIX (1885). 



