however simple its structure, or however simple the condi- 

 tions of its environment. All these subjects, therefore, are 

 included in the study of natural history, and every student 

 worthy of the name who takes an intelligent interest in his 

 work must be more or less perfectly equipped with a general 

 knowledge of these subjects, if he is to obtain satisfactory 

 results from his own studies. Not that any naturalist can 

 be supposed to have a really exact and detailed knowledge 

 of all these sciences, any one of which is sufficient to occupy 

 an individual for a lifetime ; but no man can be considered 

 a naturalist who has not mastered the general principles of 

 each, so far as it refers to his own particular branch of 

 work. 



The range of natural history, then, is a vast one, even if 

 we consider only the number of problems it presents; but if 

 we come to consider the nature of these problems, the pos- 

 sibilities to the man of intellect are unsurpassed in any other 

 field of scientific work. The great truths of morphology 

 show that all organised beings are formed upon a small 

 number of common types, and that these are to be resolved 

 into still simpler structures, the whole being referable at 

 last to simple cells which have been built up into a multi- 

 tude of forms, some of which are of the utmost complexity. 

 The facts of palaeontology show us that most of the great 

 classes of animals that exist to-day have persisted through 

 vast seons of time, endlessly modified in detail, developing 

 into slightly different forms, owing probably to a changed 

 environment producing a multiplicity of specific types, that 

 have been extinguished by developing into new forms as the 

 environment has changed, and so on until the present time 

 without losing the general appearance of the types to which 

 they belong. That these common types had their inception 

 in some simple form of life is now generally accepted by 

 scientific men, but the time when this was so goes so far 

 back that the mind utterly fails in its conception. 



The value of natural history as mental discipline is scarcely 

 equalled by any other branch of science. All education 

 should lead to the development of the human mind, and a 

 properly educated mind should be capable of readily carry- 

 ing out the processes of observation, of experiment, of 

 induction and deduction. No branch of science tends 

 more perfectly to the development of accurate powers of 

 observation than natural history, and the naturalist must of 

 necessity be able to discriminate resemblances and differ- 

 ences of the closest kind, and often, indeed, of the most 



