366 



SCIENCE. 



[N. S. Vol. II. No. 38. 



British Association, outlined tlie science 

 and traced tlie origin of the name ecology, 

 of which he made use. 



Ecology, therefore, is the name under 

 which we are to attempt the orderlj' ar- 

 rangement of the facts, observations and 

 deductions composing the science in which, 

 to quote Burdon-Sanderson, " those quali- 

 ties of mind which especially distinguish 

 the natiiralist find their highest exercise." 

 The first independent treatise on the subject 

 is bj' Wiesner (Vienna, 1889), and is an 

 excellent model, while Ludwig's work, is- 

 sued a few months since (Stuttgart, 1895), 

 which is the second and to the present time 

 only similar work, cannot be so highly 

 praised. A work in English is greatly to 

 be desired. 



Having disposed of the external or socio- 

 logical economy of the adult plant under 

 the heading of ecology, we tui-n to the con- 

 sideration of the internal or individual 

 economy. This is the portion of phj-siology 

 now in the ascendency, and the part which 

 is usually more particularljr intended under 

 the present usage of the term vegetable 

 physiology. The tendency is to restrict 

 the titular use of the term to this part of 

 the subject alone, which is to be approved. 

 This gives us three well-defined departments 

 in the science of the activities of plants: 

 caliology, ecology and phj-siology. 



Physiology, in the restricted sense, deals 

 with the most vital of problems, how the 

 individual lives. It pertains to the way in 

 which plants breathe, secure and use their 

 food, adjust themselves to light, heat, mois- 

 ture, and the contact of other bodies. It 

 deals with what botanists in the days of 

 Linnffius, and even down to within the last 

 fifty years, would have called the products 

 of the vis vitalis. It desires to know what 

 the specific energies of the plant are capa- 

 ble of accomplishing; in short, what is going 

 on within the plant in the way of life pro- 

 cesses. As will be readilj' seen, the whole 



matter is summed up in an exhibition of 

 energy, which in former daj'S was called 

 vital energy, and thought to reside exclu- 

 sively in living organisms, but now held to 

 be onlj"- a special manifestation of the gen- 

 eral physical forces of the universe. 



The energies of plants fall into two cate- 

 gories, those which bring about changes in 

 the intimate structure of vegetable sub- 

 stances, and those which bring about move- 

 ment ; and hence we call physiology a 

 superstructure whose foundation is chem- 

 istry and phj^sics. The present great ad- 

 vance in the science may, in large measiire, 

 be traced to the wonderful advances in the 

 sciences of chemistry and physics, which 

 have supplied facts and methods to as- 

 sist the physiologist in his studj' of life 

 processes. 



Yet it would be an egregious mistake to 

 suppose that j^hysiology is but a dependency 

 of chemistry and physics. The substitution 

 of the so-called mechanical philosophj' of 

 life for the old vitalistic philosophj' has not 

 in anjr way rendered the vital activities less 

 wonderful, or the protoplasmic displaj' of 

 energj^ less complex, less inscrutable, or less 

 sui generis. The meaning of the word life 

 shows no likelihood of being solved until 

 the chemical and physical constitution of 

 the protoplasmic molecule is understood, 

 and that is too far away to make specula- 

 tion at this time worth, while ; and so we 

 need not quarrel with those who fancj' that 

 even when that advanced goal is reached 

 the problem will not be solved, but a mys- 

 terious residuum will still exist to endow 

 protoplasm with autonomy. Be that as it 

 may, the path of present advancement 

 keeps steadily onward in the clear light of 

 phj'sical laws, and ignores the nearness of 

 of mj'stical, unfathomable shadows. 



But returning from this long digression 

 in separating phj-siology into the three 

 reasonablj'^ distinct sciences — caliologj-, 

 ecologj' and phj'siologj' proper — we will pro- 



