36 



Crossing the Santa Cruz river, •where its course was about 400 yards 

 wide and the stream rapid. They make but slow progress, their necks 

 are extended slightly forwards, but little of the body appears above 

 water. At Bahia Blanca, in the months of October and September, 

 an extraordinary number of eggs are found all over the country. 

 The eggs either lie scattered about, or are collected together in a 

 shallow excavation or nešt ; in the former case they are never hatched, 

 and are termed by the Spaniards Huachos. The Gauchos unani- 

 mously affirm that the malė bird alone hatches the eggs, and for 

 some time afterwards accompanies the young. Mr. Darwin does 

 not doubt the accuracy of this fact, and statės that the cock bird 

 sits so closely that he has almost ridden over one in the nešt. Mr. 

 Darwin has also been positively informed that several females lay in 

 one nešt, and although the fact at first appears strange, he considers 

 the cause sufficiently obvious, for as the number of eggs varles from 

 20 to 50, and, according to Azara, even 70 or 80, if each hen were 

 obliged to hatch her own before the lašt was laid, the first probably 

 Avould have been addled ; but if each laid a few eggs at successive 

 periods in diiFerent nests, and several hens, as is stated to be the 

 case, combine together, then the eggs in one coUection w'ould be 

 nearly of the šame age. Mr. Burchell mentions that in Africa two 

 ostriches are believed to lay in one nešt. 



Mr. Dar\vin then proceeds to notice the other species of Rhea, 

 ■which he first heard described by the Gauchos, at River Negro, in 

 Northern Patagonia, as a very rare bird, under the name of Avestruz 

 Petise. The eggs were smaller than those of the common Rhea, of 

 more elongated form, and with a tinge of pale blue. This species is 

 tolerably abundant about a degree and a half south of the Rio Negro, 

 and the specimen presented to the Society was shot by Mr. Martens 

 at Port Desire in Patagonia, (in latitude 48). It does not expand 

 its wings when running at fuU speed, and Mr. Darwin learned from 

 a Patagonian Indian that the nešt contains fifteen eggs, ■vvhich are 

 deposited by more than one female. It is stated in conclusion that 

 the Rhea Americana inhabits the country of La Plata as far as a little 

 south of the Rio Negro, in lat. 41°, and that the Pefise takes itsplace 

 in Southern Patagonia. 



Mr. Chambers then brought before the notice of the Society a 

 simple process for taking impressions from feathers, which is eflfected 

 by placing the feathers betvveen two sheets of paper, the lower one 

 being previously well damped, and the upper covered \vith printers' 

 ink; both are then passed through the rolling press of a copper plate 

 printer, and on removing the upper sheet perfect figures of the fea- 

 thers will be left, which may be coloured when dry, and will then 

 have the resemblance of feathers placed on paper. 



