Boa- Constrictors of British Guiana. 299 



wrapped, succumbs rapldlj under the enormous pressure of 

 the folds about its body. It is not often therefore that an 

 observer comes upon the field during the process, except when 

 poultry has been seized close to a dwelling and their cries 

 have attracted the attention of the inmates. 



In the case of the alligators it is far otherwise, and tlie 

 process is always a long one, taking on the character of a 

 combat, except where the snake is disproportionately Iar'>-e. 

 In one case observed the contest certainly extended over two 

 days ; and it would seem that, if the snake once succeeds in 

 infolding the alligator in its coils in an advantageous position, 

 the latter must succumb, the result being only a matter of 

 time depending on their relative size. 



In all the cases observed the contests took place in the 

 grass-covered swamp or marsh by the riverside, the alligator 

 struggling fiercely with head, legs, and tail, turning about, 

 heaving and wriggling, in a vain endeavour to cast off the 

 boa. It is remarkable that, even when the alligator is of a 

 size such that it might by wriggling reach the deeper water, 

 it seems to avoid it, perhaps from the recognition that in the 

 water, where they would both sink to the bottom, its chances 

 of holding out under the pressure of the snake's folds would 

 be lessened. 



On land the continuance of the struggle depends on the 

 crushing power of the boa and the resistance of the alligator, 

 dependent on its size, to sufibcation — a process that in these 

 mixed-blooded creatures is only effected with considerable 

 difficulty. Possibly cases may occur where a small boa 

 attempts the impossible, and has eventually to abandon it; 

 but in those that have been under observation the sizes have 

 been such that, while by means of the head, tail, and toes the 

 alligators have been able to toss and wriggle about to a greater 

 or less extent, they were evidently under stress of partial 

 suffocation. For long intervals they would remain perfectly 

 still, perhaj)s from collapse, or with the expectation that the 

 boas might consider them dead and proceed to unfold them ; 

 and then again they would struggle furiously, but equally to 

 no effect. 



It is a curious thing that under such circumstances a boa 

 will allow of quite close approach without its attempting to 

 escape or attack if interfered with, and, in fact, the same 

 thing takes place where poultry has been seized and is still in 

 the coils. Disturbance only causes the snake to bind its folds 

 tighter about its prey, as if to prevent its escape, and the 

 reptile can be easily killed — the only compensation in the case 

 of the poultry. 



