2Q2 BIOLOGICAL LECTURES. 



how it might be made of use for particular purposes ; in other 

 words, how special adaptations of a useful kind might arise. If 

 the act is a natural concomitant of the resting condition, and is 

 associated with a feeling of ease and security, we see how sick- 

 ness, injury, fear, a heavy meal, etc., might prompt it, and in 

 higher or lower degree, according to the nature and intensity 

 of the inciting cause. Full and prompt action under exposure, 

 pressure, injury, and in the event of a good meal, would carry 

 decisive advantages, so that individuals reacting in the more 

 favorable degrees would stand the best chance of escape and 

 survival. Natural selection would steadily improve upon the 

 results, and the special adaptation, in different stages of devel- 

 opment in different species, as we find it to-day in different 

 Clepsines, would lie in the direct line of progress. This view 

 does not of course presuppose intelligence as a guiding factor, 

 and therefore lends no support to the theory of instinct as 

 "lapsed intelligence," or "inherited habit." 



6. An instinct of the kind here considered does not depend 

 for its development upon effort and the transmission of func- 

 tionally acquired improvements in organization, but upon the 

 natural selection of the best qualified germs, for that is what 

 the survival of the fittest individuals always means. Many 

 species of Clepsine require but one full meal a year, and as they 

 seldom live more than two or three years, the number of meals 

 is very limited. There is little room, then, for repeating the 

 experiment often enough to affect the organization. Indeed, 

 such a supposition would here appear to be absurd in the last 

 degree. On the other hand, the selection of the fittest germs, 

 provided for in the survival of the best-adapted individuals, 

 would inevitably advance the species along the line leading to 

 the special instinct. 



If the view here taken be correct, the instinct of rolling into 

 a ball is not a matter of deliberation at all, but merely the 

 action of an organization more or less nicely adjusted to special 

 conditions and stimuli. Intelligence does not precede and 

 direct, but the indifferent organic foundation with its general 

 activities is primary; the special behavior or instinct is built 

 up by slowly modifying the organic basis. 



