134 BR. II. O. PLIMMER OX PATHOLOGICAL OBSERYATIOXS [Jan. 18, 



Tuberculosis and Mycosis have again been the cause of a large 

 number of deaths amongst the birds ; the following table shows 

 their relative incidence in the various orders of birds. 



Table IV. — Comparative Table of the Incidence of Tuberculosis 

 and Mycosis in the various Orders of Birds 



If this table be compared with a similar one for 1908 it will 

 be seen that there is no one class of bird particularly liable to 

 either of these diseases, but that their incidence depends upon 

 accident of position or infection. 



Notes on the foregoing Tables. 



The following notes refer to a few points of special interest in 

 connection with the diseases mentioned in the tables : — 



1 . It will be noticed that there is a very satisfactory decrease 

 in the amount of mammalian and reptilian tubercle in the Gardens. 

 Although there 1ms been a decrea.se also amongst the birds, there 

 has latterly been a considerable increase in the number of cases 

 in the New Bird House, mainly due, in all probability, to over- 

 crowding, but also in part to structural defects. The decrease in 

 the Reptile House appears to have been coincident with the use 

 of sand in the cages, which is constantly changed. 



2. All the cases of Mycosis have been due to the Aspergillus 

 fti.migatus. 



3. Under the term Malaria are grouped cases in which intra- 

 corpuscular parasites, belonging to either the group of Halteridium 

 or of Proteosoma, are found in sufficient number to cause death. 

 In the worst cases as many as 70 per cent, of the erythrocytes 

 have been invaded. 



4. In all the cases entered under Filaria, in Table I. there has 

 been a considerable disorganisation of the blood, and in six of the 

 birds there has been a, plugging of the cerebral capillaries by the 

 embryos of the parasite. These birds have died suddenly with 

 so-called " fits." 



On reference to Table II. it will be seen that Filaria have been 

 found in many other cases, 43 in all. Identification in most 

 instances has not been possible, as it is only in about a quarter of 

 the cases that the parent worms have been discovered. 



