754 



H I K T E L L A - H I R U N D O. 



same size as that small and very short-legsred variety 

 of the common hogf, which was first introduced into 

 Europe from the east of Asia, and is usually called 

 the Chinese breed, though we believe it came at first 

 from countries more southerly than China. The 

 remains of this species have hitherto been found in 

 France only, but we have no reason to suppose that 

 they were confined to that country, only it so happens 

 that the animal remains of France have been ex- 

 amined with more attention than those of most other 

 conntries. 



Such is a slight notice of all the leading points 

 that are known respecting one of the most singular 

 genera in the whole class of mammalia. They are 

 animals highly interesting in themselves from their 

 very singular mode of life, the powerful manner in 

 which they are armed, and the labours which they 

 perform in the general system and economy of nature. 

 But to those who wish to study the progressive his- 

 tory of the world, and read in a known language those 

 wonderful memorials of former times which are buried 

 in so many places of the earth, they are of still greater 

 importance. We find the living hippopotamus more 

 confined in the range of its pasture, and thus more 

 exclusively fitted for that pasture, than any other ani- 

 mal ; and when we examine what that pasture is, we 

 are in so far enabled to judge of what must have been 

 the state of the world when the hippopotamus was a 

 more general inhabitant. 



HIRTELLA (Wildenow). A genus of West 

 India trees, so called, from the extreme hairiness of 

 the young shoots. The flowers are pentandrious, and 

 belong to the natural order Chrysobalanece . 



HIRUNDO (Swallow, or Hirudinidcs, the Swal- 

 low tribe). A well defined family of birds, belonging 

 to Cuvier's fis&irostral sub-order of Passeres, Several 

 of the species are well known to every body from 

 their familiarity in coming close to human dwellings, 

 their labour in the building of their nests, arid their 

 rapid and graceful motions on the wing. In tempe- 

 rate latitudes they are all migrants, marking the 

 beginning of the summer by their coming, and giving 

 notice that it is over by their departure. On these 

 excursions they are generally very true to the season ; 

 but a stray one is sometimes tempted to visit the 

 warmer latitudes before our spring storms, and suffers 

 for its temerity. Hence the proverb, " One swallow 

 makes no summer," which means that we ought not to 

 found strong hopes upon slender foundations. 



Some of the family find the principal part of their 

 food over the surface of the water, for the greater part 

 of the time that they are in their northern or summer 

 haunts ; and all of them resort to the surface of the 

 water when they arrive, and most collect in flocks 

 near the waters before they depart. When natural 

 history was but little understood, the reasons of this 

 were not seen, and consequently erroneous ones were 

 alleged. This is one very remarkable instance of the 

 effect of neglecting a caution which we ought never 

 to forget when we reason beyond the facts on the 

 habits of animals, or indeed on an}' thing connected 

 with the active economy of nature. There is but one 

 truth in every case, and all eke that can be alleged is 

 error, the proportion between which is every possible 

 variety to one ; and, therefore, if a conjecture is 

 hazarded without any grounds, it is next to a miracle 

 if that conjecture shall be true. Consequently, if we 

 have no indication or any other clue to guide us to a 

 reason, in any one matter of natural history, or 



indeed in any one matter whatever, the chances ;ire 

 infinitude to one, that any reason which we may in 

 our fancy assign shall be the right one. 



This proved to be remarkably the case in the 

 matter of the swallow tribe, and so inveterate was the 

 error that naturalists, almost without exception, and 

 the great Linnaeus among the rest, fell into it, although 

 it was at variance not only with the common habils of 

 air birds, but with the whole economy of warm- 

 blooded animals. The reason assigned for this first 

 and last appearance of the swallow tribe when seen 

 skimming the surface of the waters was, that they 

 plunged into the head of the stream, where they 

 passed the winter in a dormant state, and then came 

 up again in the spring ; and some learned persons 

 alleged that they had seen the ascent from the water 

 with their own eyes, and entered into the details of it 

 with as circumstantial minuteness as if it had been a 

 truth not only within the limits of possibility, which 

 this was not, but substantiated by general evidence to 

 every part of its occurrence. This very strongly 

 shows the danger of speaking, and especially of 

 writing, upon subjects of natural history, without at 

 least some knowledge of physiology and of the general 

 laws and economy of nature ; which, by the way is 

 the reason why we have, in this work, which is framed 

 and intended expressly for general readers that is, for 

 the great body of the people, and not for mere natu- 

 ralists, have been, upon every possible occasion, so 

 anxious to blend the physiology and the relation to 

 the rest of nature with the description of every animal. 



When the least attention is given to the subject, 

 the absurdity of hybernation under water, in the case 

 of the swallows, becomes very apparent. There is no 

 warm-blooded animal that can so hybernate, not 

 even the whale or the seal ; nor does it appear that 

 they can sleep there, though they, as well as many of 

 the aquatic birds, can sleep floating upon life surface : 

 but we know of no animal that does or can hybernate 

 on the surface of water ; and, indeed, to place an 

 animal on the surface of the water would be putting 

 it in a state of peril to which we have no parallel even 

 in nature. It would be at the mercy of winds and 

 waves, and enemies of all kinds, without any means of 

 protection or power of defence ; and we may safely 

 saj r , that it would be wholly inconsistent with the wis- 

 dom and goodness of the Creator, that any one race 

 of beings should be thus abandoned to ruin. Still a 

 warm-blooded animal might exist though thus cast 

 upon the waters. Under water is another matter, 

 however ; and when once any creature has breathed 

 the pure air of heaven as part of the natural functions 

 of its living system, it -can no longer bear to be 

 immersed in a flood of the density of water for any 

 length of time. 



Swallows moult their feathers between the time of 

 their disappearance in the autumn and their return in 

 the spring ; and this is an operation which could not 

 be carried on under the water : besides, there are few 

 birds which hybernate in any way ; none, indeed, 

 which do this habitually ; for the few that have been 

 got under hedges and in other places of shelter, appa- 

 rently lifeless, have always been individuals which 

 met with hindrances which their powers were not able 

 to overcome. Even among the mammalia, the species 

 which hybernate are ail sluggish in their general 

 action, cold in their system, and slow and limited in 

 their circulation and breathing ; for even on the 

 mountain-tops, or the margins of the never-thawing ice 



