1 66 ANDREWS. 



habits. In such a set of conditions the more patent organism 

 has its origin. Now formation and function of substance 

 organs being closely dependent on presence of specific mate- 

 rials, their origin and meaning cannot be wholly inferred from 

 immediately existing conditions, but must be taken in relation 

 to race habits of the substance. Functions directly possible to 

 such organs are complex enough, but that strange interwoven 

 chemical, physical and physiological causation spoken of in 

 Heredity multiplies others intermingled with these. What, 

 causative influence may come into each substance organ from 

 any side and from long distances of space and time, for insti- 

 gation or support of any local habit, especially in the invisible 

 series, cannot be known or guessed. The excretions of one 

 substance organ can stimulate secretive function in another, 

 near or remote, this may be in turn necessary for excretions 

 of another such organ, and these again cause physiological 

 activity, as of contraction or increased irritability, in still 

 others, the products of which again act or react functionally 

 elsewhere. The products of one minute set of vesicular func- 

 tions may stimulate organs of a structure of Biitschli, and 

 these again act upon grosser or compound organs, and each 

 of all this series again react upon the prima^ry substance or- 

 ganization. Iterated or long continued function of one set 

 may be necessary for more rarely recurrent, or even chance, 

 functions of another substance organ. Chemical products of 

 invisible as well as visible substance organs may be held 

 sealed in vesicles of the finer foam, and later find their way, by 

 migrant interalveolar stuff or by blood vessels, to a perpetuation 

 or other area, there to await interactions of many other substance 

 organs before their turn for causative function arrives. The 

 whole organism may be regarded as a compound and complex 

 series of many vesicular organs for excretion and secretion as 

 well as for irritability or contractility. In this, and in the 

 rhythms of recurrence of function, all sorts and kinds of Ata- 

 vism are rooted. Every vesicle whose walls are of living func- 

 tioning substance is a true substance organ. It is secretory 

 and excretory for this which is muscle and nerve. A final 

 hypothetical vesicle whose walls should be a simple film and 



