Analytical Notices of Books. 241 
worthy of your so useful Society. Unless the Sulphur moves to some 
other part of New Holland, I fear I shall add little to your Australian 
Ornithology. 
Believe me, &c. &e. 
A. CoLLig. 
Art. XXXV. Analytical Notices of Books. 
— 
Untersuchungen ueber die Bildung und Entwickelung des Flusskrebses: 
von HEINRICH RATHKE. Mit 5 Kupfertafeln. Leipzig, 1829. 
Fol. pp. 97. 
Researches on the Formation and Developement of the Crawfish. 
Tue zoologists of this Country have been of late years so accustomed 
to direct their attention almost exclusively to animals in their perfect state, 
that to the greater number of our readers, the analysis of a work devoted 
to their illustration in the earliest stages of their developement will 
in all probability present an altogether novel subject of contemplation. 
It is for this reason especially incumbent on us to put on record 
some account of one of the most valuable contributions to animal physio- 
logy that we have met with for a considerable time. Any analysis ofa work, 
chiefly remarkable for its minute details on the minutest objects, must 
necessarily be very imperfect; but we shall endeavour, as far as possible, 
to select its leading features, so as to give a general, if not a complete, 
idea of its contents. 
While the comparative anatomists of France and England have been 
for the most part content to follow in the beaten track of observation, 
those of Germany have been exploring a new path, in which they 
have already made discoveries of the highest importance, with the promise 
of a much more ample harvest for the future. In common with the philoso- 
Voz, V. Q 
