the Ornithorynchus paradoxus. 
97 
this and some of the islands in Bass’s Straits and New 
Holland, and forming the Order Monotremata , have been 
long regarded, even by the most accomplished compara¬ 
tive anatomists, as oviparous, from their many analogies 
of structure to that of birds and other Ovipara . 
The naturalist Lesson has described the platypus, in 
his Manuel de Mammalogie , as a bird without wings ; 
and Gcoffroy has committed a still greater blunder, in 
describing the egg of some bird as that of the Orni¬ 
thorynchus. Its many analogies have strengthened the 
opinions pronounced by these great men ; and, not' 
withstanding the reasonings of Cuvier and other anato¬ 
mists, the greater number still hold it to be oviparous. 
The large ovules of the ovary, the diminutive size of the 
right oviduct, the large caracoid bones, the consolidation 
of the bones of the head, and its double superior vena 
cava, are all strong analogical evidences in favour of its 
oviparous character. 
Let us now examine the proofs of its viviparous nature. 
They seem strong, in the presence of mammary glands 
for the secretion of milk, and in the absence of an organ, 
or glaud, as existent in other Ovipara , for the secretion 
of the calcareous matter of the egg. The nutritious 
matter contained in the ovule is inadequate to the nourish¬ 
ment of the young during the period of incubation. 
The strongest proof in favour of the latter opinion is 
the character of its blood globules, which has been long 
looked upon as the experimentum crucis . 
An opportunity has now been afforded of examining the 
blood of a living male platypus, by the kindness of Mr. 
Spode. The blood was removed from the creature, and 
examined under one of Ovcrhauser’s best instruments, 
by powers of 280, 400, and 800 diameter. A small 
quantity of blood, spread upon a thin plate of glass and 
covered with a scale of mica, was placed under the field 
VOL. I. NO. II. u 
