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is specially and largely developed in the tropical zone is that of the Chiroptera or bats; which becomes suddenly much less plentiful when we pass into the temperate regions, and still more rare towards the colder parts of it, although a few species appear to reach the Arctic circle. The characteristics of the tropical bats are their great numbers and variety, their large size, and their peculiar forms or habits. In the East those which most attract the traveller's attention are the
great fruit-bats, or flying-foxes as they are sometimes called, from the rusty colour of the coarse fur and the fox-like shape of the head. These creatures may sometimes be seen in immense flocks which take hours to pass loy, and they often devastate the fruit plantations of the natives. They are often five feet across the expanded wings, with the body of a proportionate size; and when resting in the daytime on dead trees, hanging lead downwards, the branches look as if covered with some monster fruits. The descendants of the Portuguese in the East use them for fooil, but all the native inhabitants reject them.
In South America there is a group of bats which are sure to attract attention. These are the vampyres, several of which are blood-sucking species, which abound in most parts of tropical America and are especially plentiful in the Amazon Valley. Their carnivorous propensities were once liscredited, but are too well authenticated. Torses and caitle are often bitten, and are found in the morning covered with blood; and repeate attacks weaken and ultimately destroy them. Some persons are especially subject to the attacks of these bats; and as native huts are never sufliciently close to keep them out, these unfortunate in lividuals are
obliged to sleep completely muffled up, in order to avoid being made seriously ill or even losing their lives. The exact manner in which the attack is made is not positively known as the suflerer never feels the wound. The present writer was once bitten on the toe, which was found bleeding in the morning from a small round hole from which the flow of blood was not easily stopped. On another occasion, when his feet were carefully covered up, he was bitten on the tip of the uose, only awaking to find his face streaming with blood. The motion of the wings fans the sleeper into a deeper slumber, and renders him insensible to the gentle abrasion of the skin cither ls teethi or tongue. This ultimately forms ar minute lule, the blood flowing from which is sucked or lapped up by the lovering vampyre. The largest South American bats, having wings from two to two-and-halt feet in expanse, are fruit-caters like the Pteropi of the Erst, the true blood-suckers being small or of medium size and varying in colour in different localities. They belong to the genus Phyllostom, and have a tongue with horny lipuille at the end; and it is probably by means of this that they abrade the skin and produce a small round Wound. This is the account given by Buffon and Azara, and there seems now little doubt that it is correct.
Beyond these two great types--the monkeys and the lats--we look in vain among the varied forms of mammalian life for any that can be said to be distinctive of the tropics ils compared with the temperate regions. Ming peruliar groups are tropical, but they are in almost every case contined to limited portions of the tropical zones, or are rare in species or individuals. Such are the lemurs in Africa, Madagascar, and Southern Asia; the
tipirs of America and Jalaya; the rhinoceroscs and clephants of Africa and Asia; the cavies and the slotlis of America; the scaly ant-eaters of Africa and Asia ; but none of these are sufficiently numerous to come often before the traveller so as to affect his general ideas of the aspects of tropical life, and they are, therefore, o'it of place in such a sketch of those aspects as we are here attempting to lay before our readers.
Summary of the spects of Animal Life in the Tropics.-We will now briefly summarize the general. aspects of animal life as forming an ingrelient in the SClery and natural phenomena of the equatorial regions. Most prominent are the butterflies, owing to their numbers, their size, and their brilliant colours ; as well as their peculiarities of form, and the slow and majestic tlight of many of them. In other insects, the large size, and frequency of protective colours and markings are prominent features; together with the inexhaustible profusion of the ants and other small insects. Among birols the parrots stand forth is the pre-eminent tropical group', as do the apes and monkeys among mammals ; the two groups having striking analogies, in the preheusile hand and the power of imitation. Of reptiles, the two most prominent groups are the lizards and the frogs; the snakes, though equally abundant, being much less obtrusive.
Animal life is, on the whole, far more abundant and more varied within the tropies than in any other part of the globe, and a great number of peculiar groups are found there which never extend into temperate regions. Endless eccentricities of form, and extreme richness of
colour are its most prominent features; and these are manifested in the highest degree in those equatorial lands where the vegetation acquires its greatest beauty and its fullest development. The causes of these essentially tropical features are not to be found in the comparatively simple influence of solar light and heat, but rather in the uniformity and permanence with which these and all other terrestrial conditions have acted; neither varying prejudicially throughout the year, nor having undergone any import:int change for countless past ages. While successive glacial periods buve dans tated the temprate zones, anil destroyed most of the larger and more specialized forms which during more favourable cpochis has been developed, the cquatorial lands must always have remained thronged with life; and have been unintermittingly subject to those complex influences of organism upou organism, which seem the main agents in developing the greatest variety of forms and filling up every vacant place in nature. A constant struggle against the vicissitudes and recurring severities of climate must always have restricted the range of effective animal variation in the temperate and frigid zones, and have checked all such developments of form and colour as were in the least degree injurious in themselves, or which co-existeil with any constitutional incapacity to resist great changes of temperature or other unfavourable conditions. Such disadvantages were not experienced in the equatorial zone. The struggle for existence as against the forces of nature was there always less severe,—food was there more abundant and more regularly supplied,-shelter and concealment were at all times more easily obtained ; and almost the only physical
changes experienced, being dependent on cosmical or geological changes, were so slow, that variation and natural selection were always able to heep the teeming mass of organisms in nicely balancel harmony with the changing physical conditions. The equatorial zone, in short, exhibits to its the result of a comparatively contimuous and unchecked development of organic forms ; while in the temperate regions, there have been a series of periodical checks an extinctions of a more or less (lisastrous mature, necessitating the commencement of the work of development in certain lines over and over again. In the one, evolution has had a fair chance ; in the other it has had countless difficulties thrown in its way: The equatorial regions are then, ils regards their pist and present life history, a more ancient world than that represented by the temperate zones, a world in which the laws which have governed the progressive (levelopment of life have operated with comparatively little check for countless ages, and have resulted in those infinitely varied and beautiful forms--those wonderful eccentricities of structure, of function, and of instinctThat rich variety of colour, and that nicely balanced harmony of relations which delight and astonish us in the animal productions of all tropical countries.