5-'o 



NA TURE 



[Ap-il I, 1886 



with practice, about half an hour later one of the young accentors 

 was ejected : strange to say, its mother was present, and looked 

 on quite calmly, but the desperate efforts of the young murderer 

 seemed for the time to exhaust it, so that it was not until 

 I p. m. that it returned to the work and pushed out the 

 second egg, and then tried to put out the remaining ac- 

 centor. This at 3.30 was done, and the cuckoo remained sole 

 occupant. No wonder Mr. Hancock writes: — "The cuckoo's 

 proceeding, as I saw it, is, in my opinion, the most wonderful 

 and unaccountable piece of business that I ever witnessed in bird 

 life." Some of our readers may like to learn that one of the 

 unfortunate young accentors was placed in a whitethroat's nest, 

 where there were four young ones about its own age, and that 

 it was properly attended to by its foster-parents, whereas the 

 young cuckoo was, after a week's short e.xistence, found dead, 

 apparently of sunstroke, at the bottom of its nest. 



The Torture of the Fish-Hawk. — While the fact, 

 above recorded about the cuckoo are wonderful, and, from 

 a human standpoint, perhaps cruel, they would seem to 

 be surpassed in both respects by those recently recorded 

 about the fish-hawk of Southern Florida by a well-known 

 observer, J. y.zriCii.%\.tr (American Naturalist, Marcli 1886). The 

 distribution of land and water on the Gulf coast of Florida is 

 very favourable to the existence of fish, and the flats and creeks 

 swarm with life. Birds subsisting on fish diet also abound. 

 Long lines of pelicans can be seen on every hand ; armies ol 

 cranes stalk about ; fish-hawks abound. These latter are 

 arboreal in their habits, nesting in the tops of the pine-trees, ami 

 rarely resting on the ground. For the most part they fish in the 

 secluded creeks and inlets, hovering over the water and captur- 

 ing their prey by suddenly diving upon it ; but sometimes they 

 fish in the open waters. While large, active-winged birds, they 

 never soar. On first acquaintance their actions seemed inex- 

 plicable : while in the hiddeu creeks they uttered no cry and 

 seemed to be masters of the gentle art ; but in the open, allured 

 thereto by a school of mullet, at the moment when they would 

 seem eager for action and all alive with expectation, jut as they 

 might be swooping on a fish, they would emit a discordant, 

 frightened scream, and make for the shore with a haste so ill- 

 advised as to seriously impede their progress. The shelter of the 

 trees gained, the terror would subside. Desire for food would 

 tempt the bird once more out, and again and again the same 

 frantic performance was to be witnessed. The reason was soon 

 made evident. A fine specimen of the fish-hawk swooped on a 

 fish, which soon left its element and swung aloft in the bird's 

 talons. The hawk began its homeward journey. But now a 

 new-comer appeared on the scene. A black creature, which 

 seemed all wings, dropped from above and confronted the hawk, 

 which at once let go its prey and uttered a scream so brimful of 

 mortal terror as to excite one's pity. The hawk was not struck, 

 and it made oft" with wild haste for shore. The intruder was a 

 frigate-bird, w hich seized the dropped fish in its beak long ere 

 the prey reached the water, and then with a sweep of exquisite 

 grace, on tense w ings, fronting a mild breeze, the corsair was 

 lifted half a mile into the air. A bite was taken from the fish 

 by a wringing motion of the bird's head, which .'ent the carcass 

 whirling. The morsel being swallowed, the bird, folding its 

 wings tightly on its body, dropped swiftly after the fish, seized 

 it, again swept upwards, and then the performance was repeated 

 till the meal was over. In a personal contest for superiority on 

 the ground of physical strength the frigate-bird, with its small 

 legs and feet and its head and beak not stronger than the fi-h- 

 hawk's, w.as no match for the latter ; but sometimes the fish- 

 hawk does not play its part as capturer of the prey desired by 

 the frigate-bird, and several of these latter combine to cut off 

 its retreat landwards, swoop about it until the unfortunate victim 

 loses its power of screaming, then of flight ; down it falls at last 

 exhausted into the waters of the Gulf; the demon birds still 

 pursue it ; with their miserable, puny feet they alight on it, 

 and push it beneath the surface, continuing in one case to do 

 this for over an hour, until the bird was dead. When the hawks 

 captured fish they were not so treated — they were robbed, not 

 killed. It would seem as if the existence of the fish-hawk as a 

 species depended on their understanding this, and that now and 

 then those thatdid not understand lost their lives in the struggle. 



The Sensibility and Movements of Plants. — To the last 

 number of the Bitlldin de V Academic Royale de Belgiijue, the 

 late Prof. Morren contributes a valuable memoir on the sen- 

 sibility and movements of plants, in which he further developes 



Darwin's well-known theory, and attempts to establish a 

 complete synthesis of the animal and vegetable kingdoms. It is 

 argued that the law of sensation producing motion dominates 

 all the biological sciences, that plants are sensible to the in- 

 fluences of the environment, and not only move, but are able to 

 co-ordinate their movements. All the phenomena of motion are 

 referred in ultimate analysis to protoplasm, a living substance 

 common alike to plants and animals, and whose general and 

 essential characteristics are precisely the power of sensation and 

 movement. It has the faculty of receiving external agencies, 

 and of moving //t7/77'(? luotu. It stirs, therefore it lives ! And 

 this is equally true of all organisms from man to the microbe and 

 the plant. Life might be defined as the activity of protoplasm, 

 although this is a substance whose true nature is still unknown, 

 of \\'hose texture we are ignorant, and whose activity is a property, 

 the mechanism of which has not yet been discovered. 



Heredity. — The same Bulletin contains an equally in- 

 teresting paper by M. Ch. Van Bambeke, on heredity, in 

 which the theories of Darwin, Haeckel, Niigeli, Pfliiger, 

 and others are subjected to a searching criticism. Both 

 pangenesis and plastidulperigenesis are rejected, as inade- 

 quate to explain all the phenomena of heredity, which, it is 

 argued, can be accounted for only by supposing that the germ, 

 Weismann's Keiinplasma, is in fact continuous. It is not to be 

 regarded as the final outcome of the ontogenesis of each indi- 

 vidual, but passes from parent to offspring directly, being from 

 the first present in an unmodified form in a large number, pos- 

 sibly ill all the somatic cells. The germinative plasma persists 

 through certain cellular series, concentrating itself anew in the 

 embryonic cells of the new organism. In a word, in the phylo- 

 genetic development of the organisms the germ, whose true seat 

 has now been determined, is perpetuated throughout the whole 

 series of successive ontogenies. The generations succeed and 

 efface each other; the Kdmplasma alone is immortal. 



GEOGRAPHICAL NOTES 

 The progress of drying up of the steppes around the Caspian 

 Sea is i-teadily going on. Thus we learn from a recent com- 

 munication by M. Krasnoff to the Geographical Society that the 

 series of the Sarpinsk lakes in the eastern part of the Kalmuck 

 steppes, close to the Ergheni hills, are rapidly disappearing ; the 

 lakes Chilguir and Keke-tzun have quite disappeared in the 

 course of the last year. 



General Tillo publishes in the last issue of the Izvcstia of 

 the Russian Geographical Society the results of new exact 

 levellings made in order to ascertain the heights above the sea of 

 Lakes Ladoga, Onega, and Ilmen. Their respective heights 

 above the average level of the Gulf of Finland appear to be 

 only 16, 115, and 59 feet, with a probable error not exceeding I '5 

 feet. The formerly accepted heights were 59, 237, and 157 feet. 



A VERY interesting paper on the irrigation of the oases of 

 Merv and Akhal-Tekke was recently read by M. Pokrovski- 

 Kozelat St. Petersburg, before the Society for the Assistance of 

 Russian Trade and Commerce, Count Ignatiefif being in the 

 chair. The lecturer considers the Merv oasis as one of the 

 most fertile spots on the earth. Wheat, rice, and other cereals 

 cultivated by natives for home consumption yield beautiful 

 crops. The oasis includes about 900,000 acres of cultivable 

 land. But, in order to cultivate them, it would be necessary to 

 colonise the oasis with civilised pioneers, and to spend about 

 120,000/. on the restoration and extension of the splendid 

 system of canals built up by the Arabs a thousand years ago, 

 and preserved until now in some parts, as, for instance, at the 

 mouth of the River Murhab, about 50 miles from Merv. These 

 canals are 14 feet deep and 70 feet wide, and partly used even 

 now by the Merv Turcomans for the irrigation of their fields, 

 though in a primitive manner. The Akhal-Tekke oasis is not so 

 rich as that of Merv, but still it has about 900,000 acres of 

 land suitable for culture. It covers the space of 7 miles along 

 the railway line from Mikhailovsk Bay to Khizil Arvat, and 

 could be irrigated by the water from the River Tejen. 



The Imperial Russian Geographical Society has decided in 

 its Natural Science Section, to organise during the current year 

 another expedition to Central Asia, in order to investigate the 

 mountain district of Khan-Tengri, which has never yet been 

 explored by any of the European travellers in Central Asia. 



