Parked. — On the Origin of the Stermnn. . 119 



rumbling of distant thunder," was said by the Maoris to 

 be the noise caused by a great number of kakapos, " con- 

 gregated at night ;" and the time of the year -u-lien the 

 kakapos do congi-egate is agreed by all the best authorities 

 to be diu'ing the winter. On the other hand, Mr. E. 

 Henry's statement, which appears to be Mr. Melland's 

 only evidence, was that the booming was in every case 

 caused by "an adidt male kakapo," and that too during 

 the summer or breeding-season. Mr. Melland more than 

 once refers to the solitary boom heard in the Te Anau dis- 

 trict from November to March : how then can he compare 

 it to the confused din of a number of kakapos in the winter 

 time ? 



"When it is remembered that the district around Lake 

 Te Anau, and Dusky Sound, are the only places in New Zea- 

 land where li\-ing specimens of the takahe have been secured, 

 and that these places are two of the three localities where the 

 booming note has been heard, I think it probable that Mr. 

 Melland is wrong in ascribing tliis note to the kakapos of Lake 

 Te Anau, and shall continue to believe that it is the call of the 

 takahe until better evidence is produced. 



Art. XVI. — On the Origin of the Sternum. 



By T. Jeffery Parker, B.Sc, F.E.S., Professor of Biology 

 in the University of Otago. 



lI^:^d before the Otago Institute, 14th October, 1S90.] 



Plate XIX. 



According to Wiedersheim. one of the leading modern authori- 

 ties on vertebrate morphology, nothing is known of the 

 phylogeny of the sternum, in spite of the fact that its develop- 

 ment in many of the more important tN-pes has been worked 

 out in detail. 



Two kinds of sternum are distinguished by morphologists — 

 the costal sternum, formed by the concrescence of the ventral 

 ends of ribs, and found in Amniota (birds, reptiles, and 

 mammals) ; and the omosternum (coracoid sternum, or 

 clavicular sternum), formed by segmentation of the shoulder- 

 girdle, and highly characteristic of Amphibia. No trace of a 

 sternum has liitherto been described in fishes. 



In all Amniota in which a sternum occurs, its develop- 

 ment takes place in the same way. The ribs of each side 

 graduallv grow downwards, enclosing the chest. As thev do 



