WAYS AND MEANS OF LIVING 



one bud became contiguous with the one before, or became 

 enveloped by it, a relation would be established between 

 the two buds similar to that which exists between succes- 

 sive generations of life forms. The so-called parent gen- 

 eration, in other words, 

 contains the germs of the 

 succeeding generation, 

 but it does not produce 

 them. Each generation 

 is simply the custodian 

 of the germ cells entrust- 

 ed to it, and the "off- 

 spring" resembles the 

 parent, not because it is 

 a chip off the parental 

 block, but because both 

 parent and offspring are 

 developed from the same 

 line of germ cells. 



Parents create the 

 conditions under which 

 the germ cells will de- 

 velop; they nourish and 

 protect them during the 

 period of their develop- 

 ment; and, when each 

 generation has served 

 the purpose of its ex- 

 istence, it sooner or 

 later dies. But the in- 

 dividuals produced from 

 for another set of germ 

 with themselves, and so 

 persists. 



To express the facts of succession in each specific form of 

 animal, then, we should analyze each generation into germ 

 cells and an accompanying mass of protective cells which 



Fig. 64. The leg of a young grasshopper, 

 showing the typical segmentation of an 



insect's leg 

 The leg is supported on a pleural plate 

 (PI) in the lateral wall of its segment. 

 The basal segment of the free part of the 

 leg is the coxa (Cx), then comes a small 

 trochanter (TV), next a long femur (F) 

 separated by the knee bend from the 

 tibia (Ti), and lastly the foot, consisting 

 of a sub-segmented tarsus (Tar), and a 

 pair of terminal claws (CI) with an ad- 

 hesive lobe between them 



its germ cells do the same 

 cells produced simultaneously 

 on as long as the species 



103 



