NOTES. 289 



in their arrangement, and yet we know how far inferior the scorpion 

 is, on general grounds, to the vertebrate sub-kingdom. The fact is, 

 that animals are endowed with such partial superiorities, when 

 necessary with regard to the circumstances in which they are 

 destined to live ; but their place in the animal scale is to be deter- 

 mined on totally different considerations. How, if it were otherwise, 

 should we find teeth in certain radiata. and wanting in the great 

 bulk of the mollusca and articulata? How should we find this 

 branch of organization, which prevails generally in the reptiles, 

 become extinguished in the superior class of the birds, and even in 

 some of the mammalia (the manatus stelleri, for example) ? 



In plain truth, the seizing upon this fact of bidental reptiles as 

 a proof against the development theory, and that before even the 

 place of the strata in which they were found was determined, is 

 only an evidence of the rashness of the counter-theorists on this 

 question, and of the weakness of the arguments by which their 

 opposition is maintained. 



(56.) Lord's Popular Physiology. 



(57.) The numhers 1, 3, 6, 10, 15, 21, 28, &c., are formed by 

 adding the successive terms of the series of natural numbers thus : 



1=1 

 1-1-2=3 



1+24-3=6 

 l.|_24-3-j-4=10, &c. 



They are called triangular numbers, because a number of points cor- 

 responding to any term can always be placed in the form of a 

 triangle ; for instance : 



13 6 10 



(58.) Modified from one in Carpenter's General Physiology. 

 (59.) Ktrby and Spence's Introduction to Entomology. 



(60.) M. Hampe has observed in the creeping willow (salix repens) 

 that twigs above the water blossom as females, whilst those twigs 

 which have been in the water, and subsequently blossomed when the 

 water dried up, had only male blossoms. This seems a case analo- 

 gous to that of the determination of sex by the bees, and may be 

 held as an additional proof of the power of circumstances to affect 

 development to very important results. 



(61.) Gardeners' Chronicle, July 11, 1846 (Review of Vestiges 

 of Creation}. 



u 



