8 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE 
The tracings, as cut out, were laid flat in superposition, adhesion being effected by 
carefully running a heated wire along their edges. The use of colour was deemed 
desirable, but a possibility of error seemed likely to arise were the models coloured 
after completion. This, however, was obviated by colouring the tracings before they 
were cut out; and a perfectly reliable result was obtained by the use of ordinary 
oil-paint dissolved in xylol, to secure rapidity in drying. In plates thus treated, the 
melting together of their edges ensured the diffusion of the colour necessary to 
produce the final realistic result. 
4. OBSERVATIONS ON THE EaG, oN HaTcHING, AND ON THE HatcHeD YOouNG. 
During the period of Prof. Dendy’s activity, both as collector and investigator, which 
led to the publication of his two pioneer memoirs on the Development of Sphenodon 
(Dendy, 98”, 98°), there arrived in New Zealand two German naturalists—one Dr. H. 
Schauinsland, of the Bremen Museum, the other Prof. G. Thilenius, of Strasburg; one, 
if not both, of them sent out under the auspices of the Berlin Academy. Each has 
since published preliminary reports upon his investigations (¢f. List, p. 74), without, 
however, in any way alluding to Dendy’s work ; and this is the more regrettable, since 
in matters of small detail their statements both differ from and supplement his—while 
it is the more unaccountable, since one of them was permitted by the New Zealand 
Government to explore the same island as Dendy, with the aid of the very collector he 
had employed. Since neither of them has written upon the skeleton, we omit further 
reference to their work, except so far as it concerns the newly-hatched young. Dendy, 
in defining his Stage S, inclined (99*. p. 59) to the belief that the yolk is still pendant 
at hatching, and was unable to decide definitely upon his surmise (pp. 79-80) that the 
olfactory cellular-plugs which he discovered are at that period “removed.” Schauins- 
land, on the contrary, both figures the yolk and describes the nasal plug as absorbed 
shortly before hatching (98°. p. 812), and there can be no doubt he is correct. It is 
but just, however, to Prof. Dendy to state that in a letter to one of us, antedating the 
publication of Schauinsland’s notes, he had corrected his former statements (cf. letter 
to ‘ Nature,’ vol. lix. p. 340), having discovered that the embryos which had led him to 
believe that both yolk and plug might be present on leaving the egg had been 
prematurely hatched. 
Concerning the newly-hatched young, he further points out that the pineal eye is 
‘plainly indicated by an irregular scale, surrounded by eight or nine others, radially 
arranged, and all much larger than the surrounding granules,” an observation which 
we can confirm. And to this we would add that the supra-pineal area of the skin of 
the head is at hatching transparent and pigmentless, and that it remained in that 
condition throughout the four months our young ones were alive. 
Before passing to the main subject of this Memoir, we desire to record some 
observations pertinent to those communicated by us, in conjunction with Dr. Dendy, 
