s 



MODERN STEPS OF PROGRESS. 



there is probably as much complexity as in the disposition of the 

 organs of the higher animals. The variations of protoplasm are 

 astonishing ; the adaptivness to different functions unsurpassed 

 by any of the higher developed organisms. How different 

 must be the molecular arrangement in the celles of the bile- 

 producing liver from that of the cells of saliva-and again of the 

 cells of milk-producing glands ! How different a machine 

 must exist in the cells of the resin-producing glands of the 

 conifers from that of the sugar-secreting cells of the nectaries. 

 What a wide difference again must exist between the organi- 

 sation of a fungus-spore and a pollen-cell ! Only individualised, 

 specifically organised, till to the finest detail jointed and dif- 

 ferentiated structures can be the sources of the different actions 

 connected with life ! Hanstein expressed this logical conclusion 

 in the following words: "Even the most simple Protococcus or 

 Monad-cell is certainly of a complicated organisation, even if so 

 small that the best microscopes do not reveal a differentiation 

 of the cytoplasm; there is no vital action without a vital struc- 

 tured" 



But nothing would be gained from the differentiation of the 

 protoplasmatic machines, if there were no motive power. 

 What kindles then the fire, that produces the necessary steam ? 

 That "primum movens " must be united with the machine, most 

 intimately connected with it, and is absolutely necessary for 

 bringing on the most wonderful differentiations in form and 

 functions, which arise from a single original egg-cell, when 

 developing itself to an animal with the complicated system of 

 nerve, -muscles and gland-cells, with the different cellular forms 

 in epidermis and in bones. What a great variety of cellular 

 forms are found in a tree ! How many cells must sacrifice their 

 individual existence during the development of an organism for 

 the formation of tubular systems and aquaeducts ! 



How in view of these most complicated phenomena the 

 older opinion can still be defended by some physiologists that the 

 protoplasm is a varying mixture of different substances, is a " mix- 

 turn compositum ", remains incomprehensible to a logical mind. 

 Rcinke found for instance in the plasmodium of Aethalium scpticinn 

 (a fungus belonging to the mixomycetes), 27 percent of carbonate 

 1) Das Protplasma, p. 308 ff. (1880). 



