126 LIFE AND DEATH. 



comes to an end' (1. c., p. 78). The dissolution of a cell-colony into 

 its component living- elements can only be called death in the most 

 figurative sense, and can have nothing to do with the real death of 

 the individuals ; it only consists in a change from a higher to a 

 lower stage of individuality. Could we not kill a MagospJiaera 

 by boiling or by some other artificial means, and would not the 

 state which followed be death? Even if we define death as an 

 arrest of life, the dissolution of Magosphaera into many single cells 

 which still live, is not death, for life does not cease in the organic 

 matter of which the sphere was composed, but expresses itself in 

 another form. It is mere sophistry to say that life ceases because 

 the cells are no longer combined into a colony. Life does not in 

 truth cease for a moment. Nothing concrete dies in the dissolution 

 of Magosphaera ; there is no death of a cell-colony, but only of a 

 conception. The Homoplastides, that is cell-colonies built up of 

 equal cells, have not yet gained any natural death, because each of 

 their cells is, at the same time, a somatic as well as a reproductive 

 cell : and they cannot be subject to natural death, or the species 

 would become extinct. 



It is more to the purpose that Gotte has sought for an illus- 

 tration of death among those remarkable parasites, the Ortho- 

 nectides, because in them we do at any rate meet with real 

 death. They are indeed very low organisms ; but nevertheless 

 they stand far above Magosphaera, even if the latter were hypo- 

 thetically perfected up to the level of a true Homoplastid, for the 

 cells which compose the body of the Orthonectides are not all similar, 

 but are so far differentiated that they are even arranged in the 

 primitive germ-layers, and a form results which has rightly been 

 compared with that of the Gastrula. It is true they are not quite 

 so simple as Gotte l figures them, for they not only consist of ecto- 

 derm and germ-cells, but, according to Julin 2 , the endoderm is 

 arranged in two layers the germ-cells and a layer which forms 

 during development a strong muscular coat ; and in the second 

 female form the egg-cells are surrounded by a tolerably thick 

 granular tissue. There is nevertheless no doubt that in the first 

 female form, when sexually mature, the greater part, not only of the 



1 1. c., p. 42. 



* ' Contributions a ITiistoire des Mesozoaire?. Recherches sur 1'organisation et 

 le deVeloppement embryonnaire des Orthonectides,' Arch, de Biologie, vol. iii. 1882. 



