INSTINCTS ii 



progress in the form of these minute organisms ; 

 we may go further, and imagine that, if these 

 conditions exist, this incarnation may be in 

 progress now around us. 







Let us now attempt to survey and catalogue 

 the most prominent of the characteristics that 

 mark the action of Life as manifested to our 

 senses, limiting our view, in the first place, to 

 characteristics which are noticeable throughout 

 the whole of the animal kingdom, and, it may 

 perhaps be held, throughout the whole of the 

 vegetable kingdom also. 



Instincts. All living things are actuated by 

 impulses, and are guided by directions, which 

 may be conveniently styled " instincts," if we use 

 the term in a broader sense than is usually attached 

 to it. Some of them may be classed as vaguely 

 impulsive : these are illustrated by the instincts 

 of self-preservation and of reproduction. Others 

 give definite directions as to complicated methods 

 of behaviour. Directive instincts of this class 

 that particularly interest us are such skilful 

 contrivings as those by which birds build their 

 nests, bees work up their combs, or caterpillars 

 encase themselves in their cocoons. But these 

 illustrate only one of many kinds of instinctive 

 action. A caterpillar is the young of a butterfly 

 in its embryonic stage : it differs from the young 

 of a mammal, growing within the womb of its 

 mother, in that during its embryonic life it is cast 

 adrift to fend for itself ; the construction of its 

 cocoon is part and parcel of its embryonic growth, 

 and, if we style this instinctive, we must also 

 recognise as instinctive the power which enables 

 it to develop from a germ into a caterpillar, and 



