106 PLANT PHYSIOLOGY 



Robert Hooke. This eminent colleague of Newton, as is well known, 

 brought the compound microscope to a considerable degree of per- 

 fection. Moreover, to test the performance of his instrument, he 

 studied cork and other plant tissues. These incidental observations 

 led this keen-minded man to the discovery of the plant-cell. Malpighi 

 and Grew, however, went much deeper into the subject than Hooke, 

 and, as Hales and Ingen-Housz are to be regarded as the true found- 

 ers of plant physiology, so, too, Malpighi and Grew, on account of 

 their studies of the inner structure of plants, stand in the same 

 relation to plant anatomy. None of these four, however, were 

 botanists in the sense of the times in which they lived. Malpighi and 

 Grew were rather physicians, and their endeavors to learn the inner 

 structure of plants and animals led them into the then almost com- 

 pletely unexplored field of plant anatomy. The study of life was 

 of much more meaning lo these two anatomists than the business 

 which the botanists set for themselves, and so we see that they 

 associated their morphological studies w r ith the problem of life, and 

 this gave many stimuli in the direction of physiology. 



This was the situation at the close of the seventeenth century. 

 What Malpighi and Grew did, went, a hundred years later, to the 

 credit of the growing plant anatomy, while plant physiology got no 

 use from it; we have seen, then, that the founders of plant physiology 

 went to work as physicists arid chemists; their aim was a pure 

 physics and chemistry of plants; the anatomical knowledge of 

 Malpighi and Grew had not been made use of. 



Much later was the bond between plant physiology and anatomy 

 welded. This was accomplished chiefly by the so-called German plant 

 physiologists in the first third of the previous century. These were 

 plant physiologists, as a matter of fact, only in name. Unpracticed 

 in experiment, they stood aloof from the achievements of their 

 above-mentioned greater forerunners, w r hich were quite foreign and 

 incomprehensible to them. The works which they wrote on plant 

 physiology did not show what had been done in this field decades 

 before. And yet the authors of these works have done a great ser- 

 vice, in that they furthered the knowledge of anatomy, and out of 

 this sought, in a one-sided way to be sure, to explain the life of 

 plants. 



In two ways, however, the advance of plant physiology was helped. 

 First, in that these men established in Germany the relation to botany 

 of plant physiology, and, in the second place, in that they introduced, 

 besides the chemical and physical point of view already had, a 

 morphological one. 



The union of plant physiology to botany by means of anatomy 

 is easy to understand, if we note that the anatomists were first of 

 all concerned with the determination of morphological relations, 



