26 CHAPTERS ON THE NATURAL HISTORY 



the best possible results, will carry a capable naturalist through 

 almost any undertaking in which he may engage, and stamp his 

 uailv surroundings with the unmistakable mark of success. 



When we come to the material which it is our intention to ex- 

 amine, study, and describe, there is altogether another question 

 involved. The more generous the supply of material the 

 broader, clearer, and more comprehensive will be the results of 

 our researches. If possible, the amount of material examined 

 in the study of any zoological or botanical subject should be 

 sufficiently Ample as to insure beyond all perad venture a 

 thorough elucidation of every detail of structure, and the widest 

 opportunity for the data of comparison. 



Say, for example, that it is a specimen of a tortoise that com- 

 mands tlic naturalist's attention. Having obtained all the pos- 

 sible light upon its habits in nature, and its geographical distri- 

 bution, and every fact and fiction that has appeared in regard 

 to it in literature, then seize upon all the material obtainable, 

 enough in any event in order to fully exhibit the extremes of 

 variation in size; the sexual characters; the eggs, embryos, and 

 young at all stages; the fossil forms, if any are known; and 

 finally, an abundance of similar material representing all the ap- 

 parent allies of the particular form, either near or remote. 



With this before one, compare and inter-compare all of its ex- 

 ternal characters, be they of whatever nature they may. Ke- 

 study its habits in confinement, and its physiological functions 

 as far as they may be observed. Make of the specimen measure- 

 ments, drawings, and photographs to an extent to illustrate all 

 of these particulars. Next kill a series of specimens with 

 chloroform, and make full comparative dissections upon these 

 fresh cadavers, and especially with the view of ascertaining the 

 appearance, relative positions, and morphology of all the parts 

 and organs, unaffected by any preserving fiuid. Colored draw- 

 ings of all of these should be made, and then a similar series of 

 specimens be consigned to a preserving fluid, and their mor- 

 phology be re-examined, and several specimens injected (after the 

 most approved methods employed by microscopists), hardened 

 and stained, and then ;ill the tissues examined by means of a 

 lower power lens, as well as mounted sections of the same being 

 made for a complete microscopical examination, with the view of 

 making a full series of micrographs and colored drawings. 

 Having accomplished all this, we are prepared to use our labora- 



