no 



THE OOLOGIST. 



ZOOTOMY. 



The Domestic Pigeon. 

 {Concluded from March number.) 



Want of space will not permit us to 

 outline any study of the skeleton, ex- 

 cept merely to notice the skull. For 

 specimens, you should have one of an 

 adult, prepared by boiliug for some 

 time, and then carefully removing the 

 brain and tiesh; and one or two of nest- 

 lings of different ages, prepared with- 

 out boiling, leaving the bones and cart- 

 ilages articulated, The second will 

 show the different bones or cartilages 

 representing them, the location of su- 

 tures that are almost obliterated in the 

 adult skull, and other points of interest 

 which we leave the student to notice 

 for himself. A few skulls of other birds 

 and small mammals should be at hand 

 for comparison. Notice how light the 

 skull and other parts of skeleton are. 

 The skull appears to be designed to pro- 

 tect a number of delicate organs; what 

 are they and how is each protected? 

 Note shape of brain-case and cavities 

 for eyes; compare with other birds as 

 woodcock, owl, heron, etc. The large 

 hones back of, and between the orbits 

 are ths frontalis . (When sutures sepa- 

 rating bones cannot be seen in the adult 

 skull refer otthat of the nestling.) Back 

 of the frontals are the parietals. Be- 

 low the frontal and parietal is the squa- 

 mosal; the opening for the spinal cord 

 is the foramen magnum; find some oth- 

 er openings through which nerves leave 

 the brain; below, ventral to, the fora- 

 men magnum is the basioccipital; above, 

 dorsal to, it, the supraoccipital, and on 

 each side the exoccipitals; alio re the 

 supraoccipital, is a suture in the young 

 skull and a ridge in that of the adult. 

 Just anterior to the frontal are the na- 

 sal bones: anterior to the nasals on the 

 upper part of the upper mandible are 

 the premaxilla; these are ankylosed 

 with each other in the adult skull. On 



the anterior edge of the foramen mag- 

 num is a small rounded elevation the 

 occipital condyle; notice how this fits in- 

 to the cavity of the first vertebra, the 

 atlas; the slender bones anterior to and 

 below the orbits are the jugal bones; 

 these are ankylosed with the maxillae 

 in the adult, At the posterior end of 

 the jugal is the quadrate; In the lower 

 jaw-bone, forming the anterior part is. 

 the dentary; the ones articulating with 

 the skull are the articulars; note the dif- 

 ferences between these parts of the 

 adult and nestling. The auditory cap- 

 sule is an enlargement of the skull near- 

 the foramen magnum. By carefully re- 

 moving the shell covering them, the 

 semicircular canals may be seen; the 

 anterior is the largest, the posterior is 

 at right angles to the anterior; the other 

 is kuown as the horizontal; in the nest- 

 ling skull several '• — otic" bones are to- 

 be found in connection with the audi- 

 tory capsule; these are fused with other- 

 bones in the adult skull. You will find 

 it very interesting to note how many 

 bones in the nestling's skull have be- 

 come fused with others in that of the 

 adult and also how they vary in size 

 and shape in the other skulls. The- 

 above named are, perhaps, the most 

 conspicuous bones of the head Of 

 course the student will not stop here, 

 but will with the aid of some good au- 

 thor, notice the peculiarities and locate, 

 not only the other bones of the head, 

 but of the entire skeleten. He will find 

 the pigeon full of interest from the point 

 of the lull to the tips of the toes, and a 

 neverending amount of profitable study 

 may be had by comparing parts of its. 

 anatomy with corresponding parts of 

 other birds, and these with others, no- 

 ticing how they are variously modified 

 and adapted to their particular mode of 

 life. 



John O. Snydek, 

 Waterloo, Ind. 



