Ova of the Salmonidm. 225 



both of those which have and of those which have not a white, 

 seems, in its general properties, to be very similar to that of 

 birds ; I can state confidently that it is not coagulated by 

 water. The white (the glairy fluid corresponding in situa- 

 tion to the albumen ovi of birds) will probably be found to 

 possess properties differing from those of the white of the 

 bird's egg. In the instance of that of the Squalus catulus, I 

 found it was neither coagulated by nitric acid nor by heat. In 

 a note, dated Malta, 1832, I have described it " as a trans- 

 parent viscid fluid, unaltered by boiling during two minutes, 

 in which time the yolk had become hard, and uncoagulated 

 by the addition of nitric acid." 



There is a tendency of the mind to seek an object — 

 some end in all that we witness — a final cause — in accord- 

 ance with the maxim, that Nature does nothing in vain. 

 Reflecting on the property of the ova of the Salmonidse, — 

 how, so long as they retain their vitality, they remain trans- 

 parent, — how, on losing their vitality, on the undue admis- 

 sion of water, they become opaque, — it has occurred to me that 

 even this difference may not be without use. The transparent 

 ova are less easily seen than the opaque white, the living 

 than the dead ; and, in consequence, the latter may be more 

 attractive, more liable to be preyed on than the former ; and 

 the circumstance that the opaque coagulated ova resist 

 change and keep in water a long time, even several months 

 without undergoing any perceptible alteration, is in favour 

 of the conclusion, that they are specially intended for becom- 

 ing food, serving as lures, and thereby in a manner protect- 

 ing the transparent, those retaining vitality, and in course of 

 being hatched, from being devoured by birds and fishes, 



! 



On the Condition and Prospects of the Aborigines of 



Australia. By W. Westgarth, Esq.* 



1. Present Aboriginal Population. 



The information under this head is exhibited, for the sake of 



greater distinctness, in a tabular form. These returns, though in- 



— | — __ 1 „ __ — __ — — 



* The writer has confined his attention, in the following page?, almost ex- 

 clusively to the information regarding the Aborigines that has been published 

 within the last two years, which is, in general, of a more practical character 



