482 



Prof. T. J. Parker. 



[Mar. 22, 



I shall finish this paper with one more instance. In most birds the 

 true sacrals have only the upper transverse processes, or diapo- 

 physes; the lower bars, or arrested "pleuroids," are entirely gone 

 in the adult, but small prickles remain, often more on one side than 

 on the other. Thus the spaces for the large sacral nerves and their 

 ganglia, and for the lobes of the kidneys, are not quite cleared. In 

 the Tiger-Bittern (Tigrisoma leucolopJium) , a Neotropical member of 

 the " Ardeidae," there is no vertebra in the sacrum, until we come to 

 the last three uro-sacrals, that has not its inferior or "pleuroid" bars. 



The sacrum of this bird is composed of fifteen vertebrae, the first 

 has developed ribs, with imperfect sternal pieces, the next two have 

 small ankylosed ribs, separated for some distance from the diapophyses. 

 Then come three with stout generalised pre-iliac buttresses. The 

 next six have inferior rib- bars, those of the last four are strong, 

 those of the first two weak. On the left side the second of these 

 rods is membranous for a short extent ; on the right side it is im- 

 perfect in its outer part, it is a mere prickle growing from the 

 centrum. Except on the atlas this bird has ribs or rudiments of ribs 

 up to the twelfth sacral. I suspect that if the ancestral form from 

 which the Tiger-bittern arose could be put face to face with its stilted 

 descendant, the two would differ as much as the vermiform larva 

 of Ti/pula oleracea differs from its winged and stilted imago. 



V. " Second Preliminary Note on the Development of Apteryx" 

 By T. Jeffery Parker, B.Sc. C.M.Z.S., Professor of 

 Biology in the University of Otago. Communicated by 

 W. K. Parker, F.R.S. Received March 8, 1888. 



The materials for the present investigation consist of embryos of 

 the three common species of Apteryx, viz., A. australis, A. oweni, and 

 A. mantelli. Most of them, including all the earlier stages, were 

 collected for me by Mr. R. Henry, of Lake Te Anau ; a nearly ripe 

 embryo of A. mantelli was obtained from Mr. A. Reischek : and I am 

 indebted to Mme. Miiller for a half-ripe specimen of A. oweni, and to 

 Sir Walter Buller for two, somewhat older, of A. mantelli. 



I desire to record my sincere thanks to the Council of the Royal 

 Society for the grant which has enabled me to defray the expenses of 

 the investigation. 



My observations are far from complete, and deal only with com- 

 paratively late stages. The eggs of Apteryx are at all times difiicult 

 to obtain, as evidenced by their high market value, and Mr. Henry is 



bird dissected by me in having the pre-ilia buttressed by seven pairs of massive 

 processes instead of six by having only one true sacral, and by showing strong costal 

 bars on both the first and second " uro-sacral." 



