Dec. 6, 1883] 



NA rURE 



129 



principles which have been set forth by the whole essay. 

 This, therefore, we shall quote in exteuso: — 



" We have in this chapter chiefly considered the in- 

 stincts of animals under the point of view whether it is 

 possible that they could have been acquired through the 

 means indicated on our theory, or whether, even if the 

 simpler ones could have been thus acquired, others are 

 so complex and wonderful that they must have been 

 specially endowed, and thus overthrow the theory. Bearing 

 in mind the facts given on the acquirement, through the 

 selection of self-originating tricks or modification of in- 

 stinct, or through training and habit, aided in some 

 slight degree by imitation, of hereditaiy actions and dis- 

 positions in our domesticated animals ; and their paral- 

 lelism (subject to having less time) to the instincts of 

 animals in a state of nature : bearing in mind that in a 

 state of nature instincts do certainly vary in some slight 

 degree : bearing in mind how very generally we find in 

 allied but distinct animals a gradation in the more com- 

 plex instincts, which shows that it is at least possible that 

 a complex instinct might have been acquired by succes- 

 sive steps ; and which moreover generally indicate, 

 according to our theory, the actual steps by which the 

 instinct has been acquired, in as much as we suppose 

 allied instincts to have branched off at different stages of 

 descent from a common ancestor, and therefore to have 

 retained, more or less unaltered, the instincts of the 

 several lineal ancestral forms of anyone species : bearing 

 all this in mind, together with the certainty that instincts 

 are as important to an animal as their generally corre- 

 lated structures, and that in the struggle for life under 

 changing conditions, slight modifications of instinct 

 could hardly fail occasionally to be profitable to indi- 

 viduals, I can see no overwhelming difficulty on our 

 theory. Even in the most marvellous instinct known, 

 that of the cells of the hive-bee, we have seen how a 

 simple instinctive action may lead to results which fill 

 the mind with astonishment. 



" Moreover, it seems to me that the very general fact 

 of the gradation of complexity of instincts within the 

 limits of the same group of animals; and likewise the 

 fact of two allied species, placed in two distant parts of 

 the world and surrounded by wholly different conditions 

 of life, still having very much in common in their in- 

 stincts, supports our theory of descent ; for they are ex- 

 plained by it : whereas if we look at each instinct as 

 specially endowed, we can only say that it is so. The 

 imperfections and mistakes of instinct on our theory 

 cease to be surprising : indeed it would be wonderful that 

 far more numerous and flagrant cases could not be de- 

 tected, if it were not that a species which has failed to 

 become modified and so far perfected in its instincts that 

 it could continue struggling with the co-inhabitants of 

 the same region, would simply add one more to the 

 myriads which have become extinct. 



" It may not be logical, but to my imagination it is far 

 more satisfactory, to look at the young cuckoo ejecting its 

 foster-brothers, ants making slaves, the larva: of the 

 Ichneumonida: feeding within the live bodies of their prey, 

 cats playing with mice, otters and cormorants with living 

 fish, not as instincts specially given by the Creator, but 

 as very small parts of one general law leading to the 

 advancement of all organic bodies — Multiply, \'ary, let 

 the strongest Live and the weakest Die." 



PORTO RICO 

 'T^HROUGH the courtesy of Sir Joseph Hooker, we 

 ^ are able to publish the following interesting com- 

 munication from Baron Eggers on the island of Porto 

 Rico:— 



St. r/iotnas, Odol/cr22, 1883 

 Dear Sir Joseph Hooker, — It is a long time since I 

 wrote you last. I have meanwhile at last accomplished 



my long-cherished de-ign, partly at least, of exploring 

 the Luguillo Mountains in Porto Rico, which island I 

 visited during April and May this year. 



I spent about five weeks there, living for some time in 

 the hut of a " fibaro " or native labourer on the Sierra, at 

 an altitude of about 2200', on the edge of the primeval 

 forests that still cover all the higher part of the mountain 

 range. 



Since my return I have been busy arranging my coUec- 

 tioi)s, the greater part of which appears in the ninth and 

 tenth century of my " Flora Indite Occidentalis Exsic- 

 ceata.' 



As for the general character of the Sierra forests, they 

 of course resemble in their main outlines those of the other 

 West India Islands. There is, however, especially one 

 feature that strikes me as being peculiar to this mountain 

 ridge compared with the woods of other islands, for 

 example, of Dominica. Whilst the climate is just as 

 moist in the Sierra of Porto Rico as in that of Dominica, 

 the forests of Porto Rico seem nearly entirely destitute 

 of epiphytes with the exception of some few Bromeliads 

 and a very rarely occurring stray orchid. But orchids 

 in general and epiphytical ferns, such as TricJwmanes 

 and Hyi)it?wphyllum, &c , are conspicuous by their ab- 

 sence. Of palms 1 found but one species, which I have 

 distributed in my " Flora," I believe it is a Euterpe, grows 

 gregariously at an altitude from 1500' to 3000'. No Cycads 

 were seen at all. 



On the other hand, I found several interesting trees, 

 especially a beautiful Talauma, with immense, white, 

 odorous flowers and silvery leaves, which would be very 

 ornamental. The wood is used for timber, and called 

 Sabino. A Hirtella with crimson flowers I also found 

 rather common ; it is not described in any of Grisebach's 

 publications. An unknown tree with beautiful, orange-like 

 foliage, and large, purple flowers very similar in shape to 

 those of Scavola Pluinieri, split along one side, a tall 

 Lobeliacea, a large Heliconia, nearly allied, it seems, to 

 H. caribbaa. Lam., and several other as yet undetermined 

 trees and shrubs, are among the most remarkable things 

 found. 



On the whole I was somewhat disappointed with regard 

 to the result of the voyage, as 1 had expected a greater 

 number of novelties, as well as a richer vegetation in 

 general, at least something like the Caribbean Islands. 

 But these partly negative results may no doubt be of 

 some value also in forming an idea of the West Indian 

 flora in general. Of tree-ferns, Cyathea Serra and an 

 Alsophila were not uncommon. 



One of the most conspicuous trees in some parts is the 

 Coccoloba marrophylla, which I found on my first visit to 

 Porto Rico. This tree is found up to an altitude of 2000', 

 but chiefly near the coast, where it forms e.xtensive 

 woods in some places, which at the time of flowering, 

 with immense, purple spikes more than a vard long, are 

 very striking. The tree is named Ortegdn by the in- 

 habitants ; it does not seem to occur on any of the 

 British inlands, but to be confined to Porto Rico and 

 Hayti ; at least I do not see it mentioned in Grisebach's 

 " Cat. Plant, cubensium." 



The people cultivate sugarcane in the plains, which 

 are very fertile, yielding three hogsheads on an average 

 per acre without any kind of manure. Besides this 

 staple produce, a very good coffee is produced ; it does not 

 appear that any blight has as yet perceptibly aflected the 

 shrubs here. Rice is very commonly cultivated on the 

 hifls in the Sierra. I suppose it must be a kind of moun- 

 tain variety, as no inundation or other kind of watering 

 is used. Rice is in fact the staple food of the labourers, 

 together with plantain and yaiidia, i e. Caladium eseulen- 

 tiun. Immense pastures of Hymcnachne striatum (Mala- 

 hoj ilia) occupy apart of the lowland, and feed large herds 

 of cattle of an excellent quality. St. Thomas and the 

 French islands all obtain their butcher's meat fiom 



