nature study in schools. 237 



This care of their offspring was extended to such an extreme degree 

 that I found a gannet sitting on an abortive egg that was not more than 



one third the usual size. Eggs which had been spoiled did not seem to 

 to be abandoned at all and probably were never left until they actually burst 

 from the accumulation of gasses within. 



This extreme care of the eggs may be partly due to the fact that there 

 was but one, and partly to the fact that the embryo is greatly affected b\ 

 exposure. I judge that this is the case from my observation upon the new- 

 ly hatched young. They are perfectly naked when they emerge from the 

 eggs and cannot endure a few degrees of change in temperature without per- 

 ishing. I removed a young gannet, which was two days old, from the nest 

 in order to make a drawing of it, at noon time when the thermometer must 

 have stood at eighty-five degrees above zero, carried it in my collecting bas- 

 ket across the key to my house, a distance of about two miles, and when ] 

 arrived, the bird had nearly perished with the cold. I at once placed it in 

 a door way in the sun, but in a draught of air, when it revived and sat 

 up, but upon looking at it fifteen minutes later, I found it completely dead, 

 it having been killed by the^heat of the sun. 



This almost abnormal sensitiveness to change of temperature has probablv 

 increased through the fostering care of generations of parents, while it is quite 

 likely that the origin of the several species of small gannets with comparative- 

 ly delicate proportions, that occur in the tropics, can be ascribed to this habit 

 which must tend to cause physical degredation in these species. 



This hypothesis beccmes more plausible when we consider that this sensi- 

 tiveness is not exhibited to any marked degree by the naked young of the strong- 

 er, larger northern gannet, for the young of this species, when only a few hours 

 old, will live, as I have myself seen, when exposed for hours to a cold northern 

 storm. 



What better illustration could we have of the care that Nature exercise* 

 over her offsprings than this ? Operating through her mysterious laws, she has- 

 tens to supply the debilitated gannet, hatched under the burning tropical sun, 

 with a warm covering of down, while the more hardy gannet of the borral clime 

 must endure the cold without being clothed in its most helpless stage of exis- 

 tence. In the north a survival of the fittest has produced a hardy, long en- 

 during species, by simply withholding clothing at a critical period of the bird's 

 life, thus allowing the weaklings to perish that the species may survive. In 

 the south an opposite law has attained a similar result; species have been 

 evolved and perpetuated by the weakening of offsprings and consequently of ad- 

 ults. This physical weakness has, in a great measure, incapaeitated them 

 for long flights. Thus when, by chance, one or more pairs have become 



