xlvii 



Ostracoda, PhyllopocTa, and Urphyllopoda, terminating with the 

 Trilobites, Merostomidse, and Xiphosura, &c., endeavouring to 

 deduce from the forms of the larvee the comparative development 

 or descent of the higher Crustacea from the lower. The forms of 

 some of these preparatory states are certainly amongst the most 

 bizarre of the Annulose sub -kingdom. The book is dedicated to 

 Charles Darwin. 



A remarkable memoir by W. J. Schmankewitsch on Artemia 

 salina and Miilhausenii, and on the genus Branchipus, is pub- 

 lished in Von Siebold and Kolliker's ' Zeitschrift ' (Bd. xxv., 

 Suppl., noticed in ' Nature,' June 8, 1876), in which the author 

 asserts that he had observed that Artemia salina, found in a salt 

 lake near Odessa, had gradually undergone a change in the form 

 of the extremity of its post-abdomen, according to the degree of 

 saltness of the water; the bifurcation of this part of the body 

 gradually diminishing, as well as the number of its terminal 

 setse, until the tail became rounded at its extremity, with only a 

 slight central notch, agreeing in this respect and also in the then 

 smaller size of the animal, with Artemia Miilhausenii of Fischer 

 (Bull. Mosc. t. 7). The opposite experiment also showed that 

 even in a few weeks the latter species became altered in the 

 direction of A. salina, which last species, by the still greater 

 dilution of the salt water, is asserted to have been transformed in 

 the third generation into a Branchipus agreeing with the latter in 

 the post-abdomen having one more segment. Hence it is assumed 

 that the direct influence of changed conditions of life may in the 

 course of a few generations transform one species, or even one 

 genus, into another, and this in both directions. This statement, 

 however, appears to me to require much further investigation 

 than appears to have been bestowed upon it. We know, in fact, 

 from the researches of Vaughan Thompson (Zool. Besearches, 

 No. 5, pi. 2, fig. 9), that the extremity of the post-abdomen of the 

 nearly perfect Artemia salina is rounded with a slight central 

 notch, and without any spines, and that the dijBferences between 

 the terminal appendages of Artemia salina and Branchipus, as 

 well as their mouth-organs, ignored by our author, are very 

 great, whereas there is not the slightest difference between 

 the extremity of the body of A. salina and that of its supposed 

 passage to Branchipus as figured by Schmankewitsch, beyond the 

 division of the long terminal segment of Artemia into two apparent 



