Recent Ornithulugical Publications. 279 



to the Passeres — a fact which rather diminishes the value of 

 the author's conclusions, important and interesting as his paper 

 undoubtedly is. His divisions, too, seem somewhat arbitrary, 

 and require more definition than he gives of their vegetable and 

 other animal products, since these naturally have a very potent 

 influence on the distribution of the birds. 



Mr. O. Salvin has been kind enough to inform us that, in 

 Guatemala, the zones which seem to him to form the most 

 natural divisions in point of altitude are : — 1. The Hot Region, 

 extending from the sea to a height of about 4000 feet, wherein 

 the characteristic vegetation is a mixed forest, the prominent 

 trees being the Cieba, Mahogany, India-rubber, and (most con- 

 spicuous among Palms) the Coroso; Plantains also thrive best 

 here : 2. A Temperate Region, from 4000 to 7000 or 8000 feet, 

 forming the zone of Evergreen Oaks, which on the volcanoes 

 attain a great size, and are mingled with forests of Chirostemon : 

 3. The real Alpine Region, lying above 8000 or 9000 feet, with 

 upland Pines, Vacciniece, Lupins, and other true alpine plants. 

 Considerable modifications of these figures are necessary for 

 various parts of the country, the nature of the forests varying 

 much, according to the amount of moisture deposited ; but Mr. 

 Salvin believes that these divisions best group together the 

 species which have their foci in one or other of them. 



Not much need be said of the author's notes on the 

 species, except to remark that the general rule of the higher 

 the latitude the lower the range of distribution seems to hold 

 good here, the altitudes attained by birds in Vera Cruz being- 

 less than those at which the same species are found in Guate- 

 mala. Thus, in the former, Turdus grayi is believed not to reach 

 a height of 1300 metres (4000 feet), whereas in the latter it is 

 very common 1000 feet higher. Again, Icterus wagleri in Gua- 

 temala is also common at 5000 feet, while in Vera Cruz it is 

 assigned to the Hot Region — that is, not exceeding 2000 feet. 

 But we may feel assured that it is not to altitude and latitude, 

 or, in other words, to temperature alone, but also to the supply 

 of food, that we must look in a great measure for the causes of 

 the vertical range of species of birds. On the other hand, their 

 horizontal distribution seems to be traceable to changes in the 



