GENERAL PEOPEETIE8 OF LIVING MATTER. 15 



idea of irregularity, and bears no reference to a "will." This 

 motion is of two varieties : one leading to changes of shape the 

 amoeboid motion; the other to changes of place locomotion. 

 Both kinds are due to a peculiar structure of the living matter 

 in a certain stage of its development, and will occupy us after- 

 ward. Here I will only mention that, in former times, locomo- 

 tion was considered as a characteristic quality of animals. 

 To-day we are aware that a great many of the low forms of 

 vegetable life in different stages of development are endowed 

 with locomotion, apparently depending on a certain degree of 

 individual will. 



The property of producing its own kind is exclusively 

 possessed by living matter, and is also of two varieties, viz. : 

 production for the benefit of the individual itself, with the result 

 of increase of size growth ; and production of new individuals 

 generation. We know that every living body is originally 

 small ; the ovum of the largest animal is just perceptible to the 

 naked eye, but it increases by taking up nourishing material 

 from without it grows. After having reached a certain size it 

 does not grow larger, but only reproduces, renews the used-up 

 material, until at last it ceases to renew anything, and then 

 becomes what we term dead. To-day, scientists have arrived at 

 the conviction that the building-material of plants cannot be 

 essentially different from that of animals. With advancing 

 knowledge of natural philosophy, the boundaries between the 

 animal and vegetable kingdoms have more and more faded away. 

 It is impossible, in many cases, to say exactly at which point of 

 development an organism is a plant or an animal. 



It has been claimed that the only distinguishing character 

 between plants and animals is that the former feed on simple or 

 elementary inorganic material, while the latter take in organized 

 food ; but this opinion can hardly be maintained, inasmuch as it 

 is impossible to say how the lowest forms of animals are nourished 

 at all. We know, moreover, through Charles Darwin's researches, 

 that there are carnivorous plants. 



Generation. The property of generation may be looked upon, 

 in accordance with E. Haeckel's definition, as a growth of the indi- 

 vidual beyond its individual limits ; at least, every organism must 

 reach a certain degree of development before it is fit for propa- 

 gation. It is known that among the lowest forms of organisms 

 propagation takes place without sexual intercourse, whereas there 

 is a division of labor among the higher organisms, both vegetable 



