CHAPTER XIII 



OBSERVATIONS ON THE BLOOD OF GROUSE 1 



By Dr H. B. Fantham 



INTRODUCTION 



THE elements of the blood of birds are very different from those of mammals, 

 and while much is known of the histology of mammalian blood, the investigation of 

 introduc- the blood of birds has hitherto been very limited, and very little indeed is 

 known of the subject. Such literature as is available on avian blood is, 

 unfortunately, largely contradictory, and the few illustrations relating to the same 

 have not solved entirely the difficulties connected with the cellular elements of the 

 blood of birds. 



The portions of the subject that have been most adequately dealt with are those 

 relating to certain pathological conditions, fowl cholera and fowl typhoid occurring 

 in domestic fowls, and those relating to normal fowls' blood. In connection with 

 both these sets of observations there are wide discrepancies between the results 

 obtained by different investigators, and much confusion has arisen therefrom. 



The different results obtained by various investigators are partly explicable, for 

 the constitution of the blood of birds may vary among individuals of the same 

 species. Also there are differences due to age and sex, while the conditions under 

 which the investigations are made have some influence on the result. 



The chief difficulties of manipulation for the investigation of the blood of such 

 birds as Grouse are the rapidity with which coagulation occurs, and the rapid 

 alteration and disintegration that often follows the death of the blood elements. 

 The great rapidity of the onset of degeneration in the leucocytes is such that 

 extreme accuracy in counts of these cellular elements is not easily obtained, and 

 the numbers of erythrocytes and leucocytes found in different series of counts 

 consequently bear a varying relation one to another in apparently normal birds, 



1 Reprinted from the Proceedings of the Zoological Society of London, 1910. 



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