APR 24 1899 



Outlines of the Development of the Tuatara, 

 Sphenodon (Hatteria) punctatus. 



By 



Arthur Deiidy, D.Sc, 



Professor of Biology in the Canterbury College, University of New Zealand. 



With Plates 1—10. 



Table of Contents. 



PAGE 



1. Preface . . . . . . • .1 



2. Introductory Kemauks . . . . . • * 



(ff) On the Habits of the Tuatara . . . . .4 



{b) On the Time occupied in Development, with List of 



Embryos classified and arranged in Chronological Order . 9 

 (c) On the Structure of the Egg . . . . .11 



3. Systematic Account of the Stages in Development . . 14 



4. Summary and Discussion of Principal Embryological Observa- 



tions . . . . . . . -60 



[a) The Formation of the Germinal Layers . . .60 

 {b) The Formation of the Foetal Membranes . . .65 

 (c) The Modelling of the Body, and the Foundation of the Princi- 

 pal Systems . . . . • .69 



{d) The Embryonic Colour Markings . . . .77 



5. List of References . . . . . .79 



6. Description of Figures . . . . . .80 



1. Preface. 



Shortly after my arrival in New Zealand my friend Pro- 

 fessor G. B. Howes, LL.D., F.K.S., urged me to undertake 

 the investigation of the development of the Tuatara (Sphe- 

 nodon punctatus), but for various reasons 1 decided at that 

 time not to do so. Some time afterwards, however, while examin- 



VOL. 42, PART 1. NEW SER. A 



