WHITE BLOOD CORPUSCLES. 



during the chrysalis state, each texture is developed 

 anew from bioplasm, but this was derived from the 

 bioplasm of the larva. If one of the growing extre- 

 mities of a foetal tuft of the placenta be examined, it 

 will be found that the material which advances first, 

 which grows away as it were from the tissue which is 

 already formed, is a mass of bioplasm, which is di 

 vided and subdivided into smaller portions, as repre- 

 sented in Fig. 33, plate VI. The loop of vessels 

 gradually increases in the wake of this little collection 

 of living matter which continues to move onwards as 

 long as the placenta continues to grow. These little 

 collections of bioplasm bifurcate, and thus form 

 branches into which vascular loops afterwards pro- 

 ceed. As in every other instance, the first changes 

 are produced by bioplasm ; and by this living matter 

 every kind of growth and development is effected. 



White Blood Corpuscles or Blood Bioplasts. If a 

 drop of blood be obtained from the finger by pricking 

 it with a needle, and allowed to fall upon a glass slide 

 slightly warmed, covered with thin glass, and carefully 

 pressed, and then examined under a power of 700 dia- 

 meters or upwards, here and there, colourless slightly 

 granular, apparently spherical bodies will be seen 

 amongst multitudes of the well-known red blood- 

 corpuscles. These are the so-called white or colour- 

 less blood-corpuscles (Plate XVI, fig. 55). They con- 

 sist of living bioplasm or germinal matter, and exhibit 

 movements like those referred to in the amoeba and 



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