132. THE HISTORY OF BIOLOGY 



several interesting experiments on the digestion, principally on the influence 

 of the gastric juices; he obtained gastric juice from a chicken by letting the 

 bird swallow a sponge attached to a piece of thread, with which the sponge 

 was after a time recovered from the stomach drenched with gastric juice, 

 which was afterwards used for the purpose of acting upon various kinds of 

 food substances. Among his contemporaries he justly enjoyed a great reputa- 

 tion; Linnasus cites him often and with recognition, while he had many 

 pupils, of whom de Geer in particular at once carried on his work. 



Charles de Geer was born in 172.0 at Finspong, in the Swedish province 

 of Ostergotland. He was a descendant of the rich merchant and manufacturer 

 Louis de Geer, who had emigrated from Holland, and consistently with his 

 family's origin he received his education in that country. He studied at the 

 University of Utrecht, where he devoted himself to both physics and biology. 

 As a child he inherited Lovsta Foundry, in Uppland, and as soon as he came 

 of age he took over its management. He introduced a number of improve- 

 ments in the iron-manufacture and thereby acquired considerable wealth. 

 Regarded as one of the richest and most brilliant noblemen in Sweden, he 

 became in course of time Court Marshal and baron and received many other 

 distinctions. He showed great consideration for his workers, founding schools 

 for their benefit and improving their wage conditions. He was highly 

 reputed in scientific circles in Europe and was a member of several learned 

 societies. He died in 1778. 



At an early age de Geer had been interested in entomology. In this field 

 he continued the investigations begun by Reaumur, and published under the 

 same title a sequel to the latter's great work, which it in every way equals 

 in value. It comprised seven volumes, containing observations upon the 

 systematic classification of insects, their habits of life and evolutionary his- 

 tory. Although contemporary with Linn^us, de Geer did not adopt his 

 nomenclature, but retained the old method of characterizing the species by 

 means of diagnoses. Otherwise he was a keen observer, who in more spheres 

 than one made contributions of lasting value, not least in regard to the 

 lower and hitherto neglected insect-forms. 



Among the naturalists who during this period made valuable contribu- 

 tions to the knowledge of the lower animals should also be mentioned 

 Abraham Trembley (1700-84). He was born at Geneva, studied first of all 

 there, then in Holland and England, was for a time private tutor in certain 

 distinguished families, and finally became a librarian in his native town. His 

 reputation as a biologist is based upon his important monograph on the 

 fresh-water polypi. In this work he gives a careful account of a number of 

 "polypus-forms" — he includes both Hydra and Plumatella in the same 

 genus. He closely studied their habits, particularly their movements and 

 food, and was, properly speaking, the first who clearly realized their animal 



