m . 



F]-nio by J. il. Schreck 



\ ru.ACK TERX OX ITS NEST (SEE PAGE Gj/) 



Tts nest, nf rccds and grasses rather eloseh' woven, is found in grass>- marshes or in 

 vegetation tloatin.g in a slough. It is an ahuncUuit s]ieeies in the interior of the United States 

 and sul)sists eliicfly on dragon flies and various aquatic insects. 



from iiiaimiials nn the one hand and 

 front reptiles (in the other are more ap- 

 parent than real. Tbns flight, the iiKist 

 r.triking of a liird'.s gifts, is shared h\ 

 Iiats among mammals. Egg-laying is the 

 habit of most rejitiles and of three mam- 

 mals I the Anstralian dnekhill and the 

 eehidnas). lint incithation b\" r.>ne or 

 both of the ])arents is peettliar to birds, 

 though the ])\'thon is said to coil on its 

 eggs- 



I'irds breathe more rapidly than either 

 mammals or reptiles, and their pnenma- 

 ticity, or jjower of inflating numerous 

 air-sacs and e\'en certain bones, is tmique. 



The tem])erattire of birds ranges from 

 ioo° to 1 i2°,\\'hile in mammals it reaches 

 <jS° to 100°, ;md in the comparatively 

 cold-blooded reptiles it averages only 40". 



The skull in mammals articulates with 

 the last \-ertebra (atlas) I)}- two condxdes 

 or balls; in birds anrl reptiles 1:)\- onl\' 

 one. In mamm.als and birds the heart 

 has four chambers; in reptiles it has Init 

 three. 



lUKtlS ,\KI', DIvSCENDIvD EUOil I.; f, I'Tl T,t;s 



Mammals and reptiles both have teeth, 

 a character possessed li\- no existing 

 birds; Intt fossil birds apparenth' ]>rove 



that early in the de^•ell:)pment of the class 

 all birds had teeth. 



Thus we might continue the compari- 

 son, finding that birds ha^•e no universal 

 ]iecuharities of structure which are not 

 jiresent in some degree in either mam- 

 mals or reptiles, until we come to their 

 external covering. The reptile is scaled, 

 and so is the fish ; the mammal is haired, 

 and so are some insects ; but birds alone 

 possess feathers. They are worn by every 

 liird — a fit clothing for a body, which is 

 a marvelous combinatir)n of beautv, light- 

 ness, and strength. 



There is good e^'idence for the belief 

 that birds have descended from reptilian 

 ancestors. This evidence consists of the 

 remains of fossil Ijirds, some of which 

 show marked reptilian characters and, as 

 just said, are toothed. It is unnecessar\- 

 to discuss liere the relationship of the 

 bird-like reptiles, but, as the most con- 

 \incing argument in support of the theory 

 of the re])tilian descent of birds, I men- 

 tion a restoration of the .\rcha?opteryx, 

 the earliest known progenitor of the class 

 .\ves. This restoration is based on an 

 examination of jirevious restorations in 

 connection \vith a stu(h' of the excellent 

 lilates which ha\'e been published e^f the 



