LIVING SUBSTANCE 63 



free-living cells. The cell must, therefore, be the seat of those 

 events the expression of which is life. 



In opposition to this conclusion, the attempt has lately been 

 made by Altmann ( 3 90) to demonstrate a still lower stage of 

 individuality than the cell, and thus to contradict the view that 

 cells are the elementary organisms. It has long been known that 

 roundish granules of different sizes are of wide occurrence within 

 cells, lying in an apparently homogeneous ground-substance ; they 

 have been termed elementary granules, granula, or microsomes 

 (Fig. 7). In many cases only a few such granules are present in 

 the cell, in other cases the whole cell is 

 thickly filled with them, so that the ground- 

 substance between them almost disappears. 

 Altmann considers these granules to be the 

 true elementary organisms, and terms them 

 " bioblasts." He believes that they repre- 

 sent in the cell the true living elements 

 which are the seat of the vital phenomena. 



rnl it - ic T A -, r FIG. 7. Liver-cells containing 



I he Cell Itself, according to Altmann, IS tO granules. (After Altmann.) 



be considered as a colony of bioblasts, hence 



not as an elementary organism but as an individual of a higher 

 order. Of course single bioblasts cannot be kept alive when 

 separated from the other bioblasts of the cell. Nevertheless, 

 according to Altmann, there are in nature free-living bioblasts, 

 namely, the Bacteria. The great horde of Fungi or Bacteria, as 

 Altmann says, represent nothing but free-living elementary 

 organisms, which as regards individuality are equal to the granules 

 or bioblasts that in part constitute the cell-contents. 



But one searches in vain in Altmann's works for an adequate 

 confirmation of the hypothesis that the bioblasts are the elementary 

 organisms. On the contrary, it is not difficult to perceive the un- 

 tenableness of such a view. The majority of investigators have 

 not accepted it, and Altmann's attempt must be regarded as wholly 

 unsuccessful. 



The following seem to be the two most important considerations 

 which render the hypothesis of granules untenable. In the first 

 place, Altmann brings together under the conception of the 

 granule all sorts of different elements, which can by no means be 

 homologised with each other. Lately, indeed, he has given up 

 the idea that the chlorophyll bodies, which give the green colour to 

 plant-cells, are granules, but the conception still contains the 

 most heterogeneous elements. Thus, he considers as granules not 

 only the minute grey particles that occur wide-spread in the most 

 various free-living and tissue-cells, and differ greatly in chemical 

 composition and significance for the cell-life, but he includes the 

 fine granules of colouring matter in pigment-cells, which give to 

 the tissues in which they lie their characteristic colour ; the fine 



