BOOK in.] Introduction. 363 



need in the zyth and i8th centuries that a man should be 

 an Aristotelian to presuppose design and arrangements in 

 conformity with design in all parts of physiological investiga- 

 tion. This is everywhere and always the original point of 

 view which precedes * all philosophy ; but it is the part of 

 advanced science to abandon this position; and as early 

 as the lyth century philosophers recognised the fact that the 

 teleological mode of proceeding is unscientific. But the 

 first vegetable physiologists were not philosophers in the 

 stricter sense of the word, and in their investigations they 

 accepted the teleological conception of organic nature without 

 question, because they regarded it as a self-evident fact, that 

 every organ must be purposely and exactly so made as to 

 be in a condition to perform the functions necessary for the 

 permanence of the whole organism. This conception was 

 in accordance with views then prevailing, and was even useful; 

 it was no disadvantage in the first beginnings of the science, 

 that it should be supposed that every, even the minutest, part 

 of a plant was expressly contrived and made for maintaining 

 its life, for this was a strong motive for carefully examining 

 the organs of plants, which was the first thing requisite. This 

 is exemplified in Malpighi, Grew, and Hales, and we shall 

 see that even towards the end of the i;th century Konrad 

 Sprengel made splendid discoveries respecting the relations 

 of the structure of the flower to the insect world, while strictly 

 carrying out his teleological principles. The teleological 

 view was injurious to the progress of morphology from the 

 first, though the history of systematic botany shows how hard 

 it was for botanists to free themselves from such notions. 

 The case was different with physiology ; so long as it was 

 a question of discovering the functions of organs, and learning 

 the connection between the phenomena of life, teleology 

 proved highly useful if only as a principle of research. But it 

 was another matter when it became requisite to investigate 

 causes, and to grasp the phenomena of vegetation in their 



