CHAPTER XXVII 

 MORPHO-GENESIS IN LIVING AND NOT-LIVING MATTER 



MOVEMENT is one of the peculiarities to strike us first in 

 living beings, although some of them are deprived of it and 

 the seeming spontaneity of others is pure illusion. But 

 form is also a most remarkable characteristic for recognizing 

 living species. Generally speaking, we describe species 

 solely by their form ; and with a minute description of 

 this quality we are certain to recognize, everywhere and 

 always, the greater part of the living beings catalogued 

 by zoologists and botanists. 



In many cases, however, the form of a living being is kept 

 by its corpse ; and we know that the corpse is not the same 

 thing as the living being. It is always with the dead bodies 

 of animals, cut up fine to be observed under the microscope, 

 that we observe their histological structure. For this pur- 

 pose we take the precaution of killing such beings in a very 

 special way, by means of what are called fixative reagents 

 rendering the structural characters of the living being per- 

 manent in the dead body. This, of course, is very important 

 from the descriptive point of view and is besides the only 

 known process which reveals in detail the histological struc- 

 ture of living beings. But it is clear that such a method 

 stands in the way of our catching in the act the genesis of 

 forms. 



In the inanimate world we are also acquainted with char- 

 acteristic forms of chemical species the crystalline forms. 



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