236 HISTORY OF SCIENCE. 



their science a knowledge of even the most occult truths. The pre- 

 tensions of the Rosicrucians were attacked by some of the more 

 enlightened men of science ; but their doctrines had also some de- 

 fenders. 



Zoology is usually understood to include the description of animals, 

 and the methodical arrangement of them. Using this word in a more 

 extended sense, we may include under it certain branches of knowledge 

 which are sometimes treated of apart. Thus it was soon found that 

 no systematic classification of animals was of any value unless it were 

 founded on the structure of the animals ; and the knowledge of this 

 structure, which can of course only be obtained by dissection, consti- 

 tutes Anatomy. Again, the knowledge of the structure of the organs 

 of the animal body would give little information about the animal as 

 a whole, unless the actions of the various organs are studied ; and this 

 is the object of the science of Physiology. The anatomy and physiology 

 of the human body have been studied with great care, because the 

 important arts of curing diseases and of healing injuries could make 

 little progress without that kind of study. The anatomy and physiology 

 of the human body, as the bases of surgery and medicine, being thus 

 of so much practical importance, the words anatomy and physiology, 

 when used without qualification, are generally taken to imply the 

 anatomy and physiology of the human body, while, to express like 

 knowledge of the bodies of the lower animals, the terms comparative 

 anatomy and comparative physiology are employed. There is another 

 branch of zoological science upon which the practice of medicine and 

 surgery is largely dependent, and that is Pathology, which relates to 

 everything concerning diseases of the human subject especially. 



The earliest zoological writer is perhaps Aristotle, whose treatise 

 has already been mentioned (p. 28). Pliny has given a sketch of the 

 classes comprised under quadrupeds, fishes, birds, and insects ; and 

 ^ELIAN, who wrote in Greek in the second century, put forth a treatise 

 on animals which was an improvement on the writings of his prede- 

 cessors. From that time until we meet with ALDROVANDUS (1522 

 1607), an Italian, who published six large folios on zoology, the science 

 appears to have been neglected. Aldrovandus gave woodcuts of 

 many of the animals he described ; but his work is deficient in ar- 

 rangement, and contains an immense amount of matter introduced 

 without any discrimination. 



Among the ancients, the only authors who have treated particularly 

 of plants are Theophrastus (who has been already referred to on page 

 32), Discorides, and Pliny. DISCORIDES, who flourished during the 

 reign of Nero, was the author of a work on " Materia Medica" and 

 he was long regarded as the great authority for everything relating to 

 plants, and at the revival of learning, commentators were at great 

 pains to identify the particular species of plants to which his descrip- 

 tions refer. Pliny the Elder (23 79), is almost the only naturalist 



