242 PROCEEDINGS OP THE AMERICAN ACADEMY 



illustrate, but of which his desire of seeing the tropics again has pre- 

 vented the completion, he intrusts to Kunth. He has also brought 

 home animals of different classes, and distributes them among the 

 most eminent zoologists of the day. To Cuvier he intrusts the inves- 

 tigation of that remarkable Batrachian, the Aeolotel, the mode of 

 development of which is still unknown, but which remains in its adult 

 state in a condition similar to that of the tadpole or the frog during 

 the earlier period of its life. Latreille describes the insects, and Valen- 

 ciennes the shells and the fishes ; but yet, to show that he might have 

 done the work himself, he publishes a memoir on the anatomical 

 structure of the organs of breathing in the animals he has preserved, 

 and another upon the tropical monkeys of America, and another upon 

 the electric properties of the electric eel. But he was chiefly occupied 

 with investigations in Physical Geography and Climatology. The 

 first work upon that subject is a dissertation on the geographical dis- 

 tribution of plants, published in 1817. Many botanists and travellers 

 had observed, that in different parts of the world there are plants not 

 found in others, and that there is a certain arrangement in that distri- 

 bution ; but Humboldt was the first to see that this distribution is 

 connected with the temperature of the air, as well as with the altitudes 

 of the surface on which they grow, and he systematized his researches 

 into a general exposition of the laws by which the distribution of 

 plants is regulated. Connected with this subject he made those ex- 

 tensive investigations into the mean temperature of a large number 

 of places on the surface of the globe, which led to the drawing of the 

 isothermal lines so important in their influence in shaping Physical 

 Geography and giving accuracy to the mode of representing natural 

 phenomena. Before Humboldt we had no graphic representation of 

 complex natural phenomena which made them easily comprehensi- 

 ble, even to minds of moderate cultivation. He has done that in a 

 way which has circulated information more extensively, and brought 

 it to the apprehension more clearly, than it could have been done by 

 any other means. 



" It is not too much to say, that this mode of representing natural 

 phenomena has made it possible to introduce in our most elementary 

 works the broad generalizations derived from the investigations of 

 Humboldt in South America ; and that every child in our schools has 

 his mind fed from the labors of Humboldt's brain, wherever geog- 



