THE BODY. 
13 
anatomist, Nitzsch, tried the cruel experiment of starving 
a Swift to death : the poor creature did not die until six 
weeks had expired.* 
The arterial and veinous systems. in birds are not 
materially different from those of the Mammalia; the 
heart in the former is composed of two ventricles and 
two auricles, as with the latter; the arteries and veins 
themselves are also similar to those of the Mammalia, 
the pulsations of the heart, however, are more rapid 
than in mammals of similar size : this is owing to birds 
being exposed to more rapid changes of atmospheric 
pressure. 
Most singular are the respiratory organs, to whose 
wonderful distribution I have before alluded. It now 
remains to us to examine more closely the construction of 
the windpipe. This is not remarkable alone for its length; 
but, in birds gifted with voice, for the possession of a 
second larynx. First, low down in the chest we come to 
the division of the bronchia (this, in the case of the 
Humming-birds alone, takes place in the centre of the 
throat); in addition there exists in some birds, usually 
Gallinaceae, marsh- and water-birds, and especially 
among the males, a most curious detail: the trachea 
makes a variety of bends and twists, both inside and 
outside the cavity of the chest, even in the sternum 
itself. In the Crane, for example, it passes down into 
* This anecdote is scarcely credible, when we reflect on the insectivorous nature of 
the nutriment of this bird : to strengthen this observation I may mention that Dr. 
Otto Finsch, of Bremen, told me that he remembered seeing Swifts affected in a 
very different manner by the want of their natural food; he stated that on one 
occasion, in Silesia, some days after the arrival of these birds, an unusually heavy 
fall of snow so thoroughly cleared off all the insects that in three or four days Swifts 
were to be found dead on the ground through starvation, though, in this case, it 
must be confessed the unusual change of temperature may have accelerated death. 
—W. J, 
