ioo ON THE ORIGIN AND [CHAP. 



differentiation between the exterior and the interior: 

 the body being more or less distinctly divisible into an 

 outer layer and an inner parenchyme. In the Amcebas, 

 as in Protamceba, multiplication takes place by self- 

 division, and nothing corresponding to sexual repro- 

 duction has yet been discovered. 



Somewhat more advanced, but still of great simpli- 

 city, is the Protomyxa aurantiaca (PL 5, Fig. 8), dis- 

 covered by Haeckel 1 on dead shells of Spirula, where 

 it appears as a minute orange speck, which shows well 

 against the clear white of the Spirula. Examined 

 with a microscope, the speck is seen to be a spherical 

 mass of orange-coloured, homogeneous, albuminous 

 matter, surrounded by a delicate, structureless mem- 

 brane. It is obvious from this description that 

 these bodies closely resemble eggs, for which indeed 

 Haeckel at first mistook them. Gradually, how- 

 ever, the yellow sphere broke itself up into smaller 

 spherules (PI. 5, Fig. 9), after which the containing 

 membrane burst, and the separate spherules, losing 

 their globular form, crept out as small Amoebae (PI. 5, 

 Fig. 6), or amoeboid bodies. These little bodies moved 

 about, assimilated the minute particles of organic 

 matter, with which they came in contact, and gradually 

 increased in size (PL 5, Fig. 7) with more or less 

 rapidity according to the amount of nourishment they 

 were able to obtain. They threw out arms in various 

 directions, and if divided each section maintained its 

 individual existence. After a while their movements 

 ceased, they contracted into a ball, and again secreted 

 round themselves a clear structureless envelope. 

 1 Monographicder Moneren, p. 10. 



