^"'I'oi^' ] Cleland and Johnston, Red Blood Cells. IQI 



to 14.5, usually being about 14, whilst Merops averaged decidedly 

 less, being 11 to 12.5, and thus approximating to the Coccyges, 

 which varied from 11.5 to 13. Nine species of the Psittaciformes 

 varied more amongst themselves, the average being about 12.5, 

 but measurements of 11 to 13.5 were not uncommon, and oc- 

 casionally 14.5 was noted. The cells of Cacatua leadbeateri, given 

 as 16 to 17. were almost certainly artificially enlarged. Seven 

 species of Colnmbi formes gave on the whole very uniform results, 

 being in most cases I2;5 ; occasional ranges to 14.5 were noted, 

 and in two specimens of Ocyphaps lophotes the readings were 14 

 to 15, but we must consider this as due to some artefact increasing 

 the size. Amongst the Passeriformes we find some remarkably 

 constant results and some interesting grouping. The Campo- 

 phagidce and Corvidce were the largest, usually being 12.5 to 13, 

 but varying from 11 to 14. The families Timeliidce, Attamidce, 

 Prionopidce, Laniidce, Sittidce, Certhiidce, and PloceidcB. rarely 

 varied outside 11 to 12.5. Sylviidce, Oriolidce, DicruridcB, and 

 Ptilonorhynchidce seemed to exhibit a slightly smaller size, 10.5 

 being a frequent minimum. One Hirundinidce gave 11, and it 

 may perhaps be associated with the MuscicapidcB, which varied 

 from 9 to 1 1.5, and occasionally 12-5. Nine species of the 

 Meliphagidce. gave on the whole very uniform results, usually 

 being from 10.5 to 11. 5, occasionally more. 



As birds own a reptilian ancestry, in the most archaic forms 

 we would expect to find the largest red cells. This seems to be the 

 case. In the sequence of orders given by Evans, we find the first 

 one we have to deal with is that of the Colymbiformes, in which 

 he places Podiceps. Evans says this order is very archaic and 

 holds a somewhat isolated position. It stands high on our list 

 (only one bird was examined) as regards size. Evans's next order 

 is the Sphenisciformcs (Penguins), one of whose nearest allies is 

 the order Colymbiformes : Sphenisciformes stands second on our 

 list. In Evans's Ciconnformes are included the Ardeiformes 

 and Pelicaniformes. standing first and fourth on our list — though 

 there is really little difference between these upper groups. Next 

 comes the Falconiformes of Evans, which our figures would place 

 further on. His next order, Galliformes, fits in with our findings, 

 though perhaps the Charadrii formes (in our sense; should precede 

 them in point of size. Evans plac( s in the Charadriiformes, Lari 

 and Coliimba', as well as Limkolcv. As regards Coliimbce, our 

 findings distinctly remove them from this group. The Coracii- 

 formes, as regards the genera Dacelo and Halcyon, come before the 

 Cuculiformes, to which latter Merops is perhaps more closely 

 related. The Psittaci, which Evans groups with the Cuculiformes, 

 agree with their position. After these we would place the 

 Pigeons. Finally, we come in both cases to the Passerines. 

 Amongst these some interesting results are seen. The largest 

 cells appear to be in the families Campophagidce and Corvidce. 

 These two families are third and twenty-fifth respectively in 

 Mathews' list : Evans places them as 12 and 2^, but, in speaking 



