18 PHYSIOLOGY CHAP. 



Much work has been done with the object of determining the 

 changes iii the blood after thyroidectomy, but has led to no 

 concordant results. The number of the erythrocytes and the 

 amount of haemoglobin diminishes according to some authorities, 

 according to others it remains approximately invariable. The . 

 quantity of oxygen fixed by the haemoglobin of dethyroidised 

 dogs may diminish, or remain approximately unaltered, according 

 to the nature of the pathological phenomena at the moment of 

 investigation. The isotouic coefficient of the erythrocytes is 

 somewhat reduced, owing probably to the altered metabolism 

 (Bottazzi). The proteins of the plasma alter in their qualitative 

 relations : at first there is a relative diminution of globulins and 

 increase of serin ; later, on the contrary, the serin diminishes, 

 while the globulins relatively increase (Ducceschi). This fact 

 depends probably on the state of almost complete inanition in 

 which the dethyroidised dog exists, also on the albuminuria 

 frequently observed in these animals (Herzen), owing to which 

 a predominating amount of serin passes into the urine. 



Coronedi's recent and systematic researches on this albumiuuria 

 have shown it to be a constant phenomenon, although it varies 

 in intensity. It sometimes precedes the onset of characteristic 

 symptoms of thyro-parathyroid deficiency, more particularly the 

 convulsions. It is curious that this albuminuria can as a rule 

 be detected most certainly by means of Esbach's citro- picric 

 reagent. 



In addition to albuminuria, glycosuria is often seen in 

 dethyroidised dogs. It usually sets in two days after the opera- 

 tion (so that it is not the effect of post-operative traumatism), 

 and lasts, sometimes intermittently, till death (Falkenberg, Gley). 

 According, however, to the later and more accurate work of 

 Coronedi, the reducing power of the urine is seldom due to 

 dextrose. Coronedi and Luzzato further noted in dogs that the 

 reaction of the urine became alkaline after parathyroidectomy, 

 owing to the presence of free ammonia. 



Such are the principal pathological features exhibited in dogs 

 after complete ablation of the thyro-parathyroid apparatus. They 

 present a less acute course than the typical cases of tetany in man, 

 and a much more rapid course than Kocher's cachexia. This 

 greater rapidity doubtless accounts for the absence of myxoedeina 

 in dethyroidised dogs, i.e. swelling owing to infiltration with 

 mucin. In the dogs which, as a rare exception, lived for some 

 time after thyroidectomy, Tizzoni and Centanni (1890) saw that 

 trophic phenomena similar to myxoedenia did make a tardy 

 appearance. Coronedi and Marchetti have recently described 

 two typical cases of experimental myxoedeina in such animals, 

 the psychical decadence being also particularly pronounced. 



In thyroidectomy practised on monkeys (which by their greater 



