1859.] on tlie Ckronometry of Life. 123 



not before the same month in the third year." (Vol. iii. p. 264.) The 

 design of so singular an arrangement is, as they observe, to secure that 

 insects, coming into active life in February or March, may not be 

 utterly exterminated by the ungenial weather of a single season, or of 

 two such seasons in succession : but the very cause of the differences 

 among the pupae, in their relations to the same external conditions, 

 must be in their own properties. 



A somewhat similar instance of apparent complete likeness among 

 seeds in all respects except that of time, is in those of a Begonia, which, 

 if taken from the same pod, and all planted together, and all kept in 

 the same conditions, will germinate, some in a day, some at the end of 

 a year, and some at various intermediate times. 



To these indications of self-dependent time-rates in the lower 

 organisms, might be added all the facts of another class, which show 

 punctuality in the adjustment of several distinct processes. Scarcely 

 an event of life could be watched which would not show it. 



[The instance by which it was illustrated, was that of a Saxifraga, 

 whose stamens, like those of Parnassia, arrive at their very maturity, 

 not all together, but in pairs, and in pairs bend upon the pistil, each 

 pair rising again before another pair bends down.] 



And, lastly, the influence of temperature on the rate of the forma- 

 tive processes in the lower organisms is scarcely, or not always, 

 greater than that of nutriment and other external conditions, is on 

 their quantity. The occurrence of " good " and " bad " seasons indi- 

 cates the latter influence, as that of " early " and "late" seasons does 

 the former. Plants of the same species growing, some in an arid, others 

 in a rich soil, differ exceedingly in size ; the one are stunted, the 

 others exuberant ; here nutriment modifies the quantity of formation 

 as, in other instances, varieties of heat will modify its rate. But this 

 being so, it may be held that as a certain average size or quantity of 

 growth is a characteristic of each species, and an issue of its very 

 nature, so is a certain average ^time or rate of growth. Quantity and 

 rate may alike be varied by external circumstances, but the standard 

 or medium of both, as well as the limits of variation compatible with 

 life, are determined by the natural and inherent properties of the 

 species. 



Whatever evidence these and the like facts might supply, that, in 

 connexion with the seasons, the time-rates of the organic processes in 

 the lower organisms are essentially dependent on the inherent proper- 

 ties of each organism, similar evidence might be adduced for the 

 case of the higher, and especially the warm-blooded animals. In these 

 the varieties of seasons have less influence in modifying the rate, as 

 well as all the other measures, of life ; and the less influence, the higher 

 the species, or the degree of development of the individual. Moreover, 

 there are in birds some instances in which organic processes have a 

 tendency to observe certain times of the year even when the seasons 

 are changed. Thus among those brought from Australia to this 

 country, some of the parakeets breed here in December ; the black 

 swan sometimes breeds in November as well as in May ; the New 



