28 Animal Life and Intelligence. 



the life of the organism, when well supplied with nutri- 

 ment, the cells multiply rapidly, by a process of fission, 

 or the division of each cell into two daughter cells. The 

 first part of the cell to divide is the nucleus, the proto- 

 plasmic network of which shows, during the process, curious 

 and interesting arrangements and groupings of the fibres. 

 When the nucleus has divided, the surrounding protoplasm 

 is constricted, and separates into two portions, each of 

 which contains a daughter nucleus. 



In addition to the multiplication of cells, there is the 

 formation, especially during periods of growth, of certain 

 products of cell-life and cell-activity. Bone, for example, 

 is a more or less permanent product of the activity of 

 certain specialized cells. 



There is, perhaps, no more wonderful instance of rapid 

 and vigorous growth than the formation of the antlers of 

 deer. These splendid weapons and adornments are shed 

 and renewed every year. In the spring, when they are 

 growing, they are covered over with a dark skin provided 

 with short, fine, close-set hair, and technically termed "the 

 velvet." If you lay your hand on the growing antler, you 

 will feel that it is hot with the nutrient blood that is 

 coursing beneath it. It is, too, exceedingly sensitive and 

 tender. An army of tens of thousands of busy living cells 

 is at work beneath that velvet surface, building the bony 

 antlers, preparing for the battles of autumn. Each minute 

 cell knows its work, and does it for the general good so 

 perfectly is the body knit into an organic whole. It takes 

 up from the nutrient blood the special materials it requires ; 

 out of them it elaborates the crude bone-stuff, at first soft 

 as wax, but ere long to become as hard as stone ; and then, 

 having done its work, having added its special morsel to 

 the fabric of the antler, it remains embedded and immured, 

 buried beneath the bone-products of its successors or 

 descendants. No hive of bees is busier or more replete 

 with active life than the antler of a stag as it grows 

 beneath the soft, warm velvet. And thus are built up in 

 the course of a few weeks those splendid "beams," with 



