and their Classification. 287 



aware of it as heat, until it occurs about four hundred trillion 

 times, when it impresses us as light, and beyond about eight 

 hundred trillion times as chemical force or chemism. °In 

 treating of the different effects upon our consciousness of 

 motion repeated with greater or less rapidity in a unit of 

 time, dynamology embraces as subdivisions the particular 

 sciences which treat of these different modes of motion, as 

 phonology, photology, etc. 



Of morphology some portions have been well cultivated 

 while some have been neglected. The forms, or states of 

 cohesion, in which matter is found, as solid, liquid or gase- 

 ous, have given rise to the subdivisions stereology, hydroloffy 

 and aerology, to which must probably be added etherology'to 

 embrace the fourth or etherial state, of which, however? not 

 much is as yet known. From another point of view, I may 

 say that moiphography has been investigated more than 

 morphogeny. A part of metageo-morphography (especially 

 that relating to the sun, its protuberances, etc., called helio- 

 morphography) has lately been studied with renewed zeal, 

 since heliohylology (the chemistry of the sun) has been 

 made possible by the discovery of spectrum analysis. Of 

 abio-morphography, the portion to which especial attention 

 has been given, is crystal lograjihy in connection with miner- 

 ology. Biomorphography is ordinarily termed anatomy, and 

 the advances made in this science, especially in zoomorphog- 

 raphy or animal anatomy (or zootomy as it is sometimes 

 called), have been principally due to the needs of medicine 

 and the researches of physicians. Biomorphogeny has been 

 well divided by H^ckel into ontogeny (the science of the 

 development of "onta,"^•.e. organic individuals), correspond- 

 ing to what is ordinarily called embryology, and phylogeny 

 (the science of the development of "phyla," i, e. orgiinic 

 stocks or races) corresponding to ordinary palfebntoloo-y. 

 The scientific investigation of both is a matter of recency. 

 Until comparatively lately, fancy and hypothesis held the 

 place of knowledge in both these branches. 



MARCH, 1873. 20 An:n. LYC. NAT. HIST., VOL. X. 



