PREFACE. 



To a work comprising such an extensive body of science as the 

 Handbook of Zoology of Prof. VAN DER HOEVEN, it is impossible 

 that in a few years or even months much matter for additions and 

 corrections should not be presented. It is clear, moreover, that 

 the printing of a book of more than 800 pages, like the first 

 volume of the English Translation, cannot be completed in a few 

 weeks. The English translator, therefore, could not avail himself 

 of the contributions of Prof. LEUCKART who, in the beginning of 

 1856, gave a supplement to the first volume of the German edition 

 (Nachtrage und Berichtigungen zu dem ersten Bande von J. VAN 

 DER HOEVEN'S Handbuch der Zoologie, printed after the translation 

 of the second volume, Leipzig, Leopold Yoss, 1856). At the date 

 of that publication the greatest part of the first volume of the 

 English edition had been already long printed. From the same 

 cause also reference to the second edition of Prof. OWEN'S Lectures 

 on the Compar. Anatomy and Physiology of the Invertebrate Ani- 

 mals, was for the most part impossible. 



The English translator, however, gave in the body of the first 

 volume additions and remarks in great part similar to those which 

 are to be found in LEUCK ART'S comprehensive review of the pro- 

 gress of Zoology during the six or seven years subsequent to the 

 publication of the first volume of the original. In the chapter on 

 the Iniusories he made a large use of Prof. STEIN'S observations. 

 Amongst these the affinity asserted to exist between Vorticellce and 

 AcinetcB would seem to have been disproved by Dr LACHMANN 

 (MUELLER'S Archiv f. Anat. u. Physiol 1856, pp. 340398), who 

 followed the roving embryos from Acinetae until, having fixed 

 themselves, they lost their cilia and developed the peculiar suctorial 



