IGO BOARD OF AGRICULTURE. 



for more than two hundred years, this subject has received the 

 earnest attention of enthusiastic and talented students in vari- 

 ous countries, the most iUustrious, of whom,* our own col- 

 league, has informed us that Professor Bischoff spent twenty 

 years in observing the embryology of only four species of 

 animals, and that he himself, with the ablest assistants, has 

 devoted several years to the embryology of turtles. He has 

 also stated that for one series of observations upon the changes 

 occurring within a hen's egg during the first hours of incuba- 

 tion it was found necessary to open for examination three 

 thousand specimens, and that so much talent, skill, time and 

 apparatus are requisite for such investigations that almost 

 nothing is yet known concerning the embryology of our 

 domestic animals, the intelligent breeding of which consti- 

 tutes a most important department of agriculture. 



If now such well-nigh insuperable obstacles oppose inquiry 

 concerning the changes which occur in the almost transparent 

 gelatinous material of an egg, out of which the various 

 organs and fluids of the complete animal are developed, we 

 can hardly expect greater success when attempting to study 

 the phenomena attending the reproduction and growth of 

 plants. The hardness and opacity of the seed, the complexity 

 of its chemical constitution and the exceeding simplicity of its 

 cellular tissue, within w^hose secret chambers the processes of 

 vegetation are carried on, all conspire to bewilder and discour- 

 age the investigator. 



If two perfect fresh seeds from the ripe catkin of a willow 

 be selected and placed, the one in warm damp earth and the 

 other upon a shelf in a dry room, they will both change 

 rapidly. The former, absorbing moisture and oxygen, within 

 twelve hours begins to grow, the integuments burst and the 

 young root emerges and strikes with unerring instinct into the 

 moist soil, apparently under the influence of the force of gravi- 

 tation. The plumule on the other hand struggles upward 

 towards the light and air, and in opposition to the earth's at- 

 traction, rises toward the sky. This tendency of these two 

 portions of every vegetable embryo to expand, the one into 

 the earth and the other into the atmosphere, where each has 

 its proper function to perform has been known as long as any 

 botanical fact, but who can explain it ? AVhile under the genial 



