4 ARTHUR DENDY. 



hardened in Kleinenberg's picric acid after removal from the 

 egg, and preserved in alcohol. Those which were required for 

 sections were stained with borax carmine, and cut in paraffin 

 with Jung's sliding microtome. I found it desirable to use oil 

 of cloves for clearing the embryos previous to embedding in 

 paraffin, as this allowed of more advantageous examination of 

 them as transparent objects than the turpentine method which 

 I usually employ. 



It would, of course, be impossible in the time which I have 

 had at my disposal to give anything like a complete account of 

 the development of the Tuatara; and in this communication I 

 propose only to give a general outline, with special reference 

 to the formation of the germinal layers, the foetal membranes, 

 the modelling of the body, the foundation of the principal 

 tystems, and the classification of the embryos into stages; 

 which will, I hope, be useful in future investigations either by 

 others or by myself. 



This general account may be followed by more special 

 memoirs dealing with the development of the particular organs. 

 Already, indeed, I have sent home for publication one such 

 memoir " On the Development of the Parietal Eye and adjacent 

 organs." 



In concluding this preface I must express my sincere 

 gratitude to Professor G. B. Howes for his kindly interest and 

 encouragement, and for revising the proof sheets, and super- 

 intending the execution of the plates in my absence from 

 England. 



At my request he has undertaken to investigate the deve- 

 lopment of the skeleton, and for this purpose I am forwarding 

 to him a supply of material. 



2. Introductory Remarks. 



(a) On the Habits of the Tuatara. 



Since I have not myself visited Stephens Island, it will be 

 as well to give the following account of the habits of tiie 

 Tuatara as nearly as possible in Mr. Henaghan^s own words. 



