Mar. 12, 1 8 74 J 



NATURE 



363 



here on the horns of a dilemma. He evidently puts the cart 

 before the horse. It is the movements of the heart which deter- 

 mine the movements of the blood, and not the converse. 



The cardiac movements are dae to a change of shape in the 

 sarcous elements or ultimate particles of the muscular fibres of 

 the heart, and in the adult organ can only b= effected by a vital 

 and alternate elongation and shortening of all the fibres composing 

 the heart ; the elongation occurring during the diastole and the 

 shortening during the systole. Similar remarks are to be made 

 of the voluntary muscles which, as stated in my work on " Ani- 

 mal Locomotion," are endowed with centrifugal and centripetal 

 movements. 



That the opening and closing of the ventricles of the heart are 

 in no way connected with the passage of blood through the sub- 

 stance of the organ, is proved indirectly by the miivemen s of 

 the heart of the embryo. Here the heart opens and clo'-es with 

 time-regulated beat, while yet a mass of cells, and before it 

 contains blood either in its cavities or in its substance. But that 

 the presence of blood is not necessary to such movements is 

 placed beyond doubt, for rhythmic movements occur in the 

 vacuoles of certain plants, as e.g. the Volvox globator, Gonium 

 pectoraie, and Chlamydonwnas, where no blood is present. 



Lastly, if a frog be slightly curarised and its spinal cord 

 destroyed, it is found, on exposing the heart, that the sinus 

 venosus, vena cava inferior, the auricles and ventricles are quite 

 destitute of b'ood, and yet the organ beats normally and with the 

 utmost regularity. Mr. Garrod has consequently not yet suc- 

 ceeded in answering my query as to how the di .stole of the left 

 ventricle is produced He has failed to show that it is not 

 effected by the active elongation or centrifugal movements of all its 

 fibres. J. Bell Pettigrew 



Lakes with two Outfalls 



Having observed the discussion lately carried on in your 

 pages as to the existence of lakes with two outfalls, I think the 

 following description of such a lake by Prof Bell, of the Geolo- 

 gical Survey of Canada, may be interesting to some of your 

 readers. It occurs on the summit of the high Laurentian 

 country between Lake Superior and Hudson's Bay : — 



" In crossing the country from Lake Nipigon to the Albany 

 River, we first followed the Ombabika River to its source, 

 which is in Shoal Lake, three and a half miles long and one 

 mile wide, lying at a distance of twenty-five miles north-east of 

 the mouth of the river. This lake lies due north and south, and 

 discharges both ways, the stream flowing northward towards the 

 Albany, called the Powitik River, being nearly as large as the 

 southern outlet. No portage occurs on the Ombabika for about 

 nine miles before reaching Shoal Lake, nor for nearly five miles 

 beyond its northern outlet ; so that we passed the height of 

 land with the greatest possible ease, having had about seventeen 

 miles of uninterrupted canoe navigation, from the time we made 

 the last portage, in going up the southern side, till we came to 

 the first on going down on the northern. Shoal Lake has an 

 elevation of scarcely 300 ft. over Lake Nipigon, or about 1, 200 ft. 

 above the sea." — " Report of Progiess Geological Survey of 

 Canada for 1871-72," p. 107. George M. Dawson 



Montreal, Feb. 19 



The Ink of the Cuttle-fish 

 With reference to the interesting account in Nature, vol. ix. 

 p. 332, of a gigantic Cephalopod captured in American waters, 

 and of a still larger one, which attacked the boat belonging to 

 some fishermen near Newfoundland, by twining its arms round 

 the vessel, and whicli, having had two of those arms cut off by 

 the fishermen, moved off, " ejecting a large quantity of inky 

 fluid to cover its retreat," I desire to draw attention to an ob- 

 servation respecting this fluid, which I made on the occasion of 

 a visit to the Crystal Palace Aquarium. My friend Mr. Lloyd 

 was good enough to dislodge a cuttle from its place of conceal- 

 ment, and the usujI inky discharge followed, as the creature shot 

 across the tank. Mr. Lloyd states in his interesting " Hand- 

 liook to the Marine Aquarium," "that the ink (which is viscid) 

 does not generally become diffused through the water as writing 

 ink would be, but is suspended in the water in a kind of com- 

 pact cloud tdl it gradually settles down, and is dispersed in 

 flakes." Now I quite think, with Mr. Lloyd, that this Being the 

 case. It is difficult to perceive how, according to the generally 

 received opinion, its retreat is covered by the ejected cloud. It 

 seems to me more likely that this discharge is to divert the at- 



tention of a pursuer — a dog-fish for instance — which would for 

 the moment be startled by the surtden appearance of masses of 

 dark colour in the water, and in the confusion the cuttle makes 

 his escape. 



Now that public aquaria are becoming so general in our great 

 towns, it is much to be hoped that this and many other interest- 

 ing problems in marine zoology may be solved. 



Birmingham, Feb. 28 W. R. Hughes 



Transmission of Light in a Squall 



On the Admiralty Pier, Dover, during a "squally" gale, I 

 rernarked an occasional jerking or unsteadiness in one of the 

 adjacent lights, say two miles off, to one of the coast-guard's 

 men with whom I was talking at the time. 



To him this was a well-kn )wn observation in squally weather. 

 At times, he said, two lights could distinctly be seen for a 

 second or so ; frequently the shape of the light was changed, by 

 elongation, vertically and horizontally. 



The above phenomenon, if not generally known, might be 

 worth noticing and verifyin in your excellent paper. 



I suppose an explanation is to be found in the different 

 densities of the atmosphere through which a ray of light must 

 pass in rough unsteady weather ; the second imasje being simply 

 the persistence of the one s-en immediately before the change 

 in position of the ray by relraction. James C. Inglis 



DR. LIVINGSTONE AND THE CAMERON 

 EXPEDITION 

 T N Nature for Feb. 26, we expressed the desire which we 

 ^ felt, in common with our readers, for information re- 

 specting the orders that have been sent to Zanzibar as to 

 the disposal of Dr. Livingstone's body. We now have 

 great pleasure in being able to announce that Lord Derby 

 acted with the promptitude and energy which might be 

 expected from a statesman who has always shown a warm 

 sympathy for the cause of geography. With the concur- 

 rence of the family, his Lordship has sent a telegram 

 ordering the body of the illustrious traveller to be sent to 

 England, and we believe that it is to be accompanied by 

 one or two of Livingstone's faithful negro followers. 



The melancholy death of Dr. Dillon and the return of 

 Lieut. Murphy, leaves Lieut. Cameron alone, to proceed 

 to Ujiji, to recover the box of papers left there by Living- 

 stone, and to prosecute further geographical exploration. 

 Heavy unforeseen expenses obliged Lieut. Cameron, who 

 has proved himself to be a resolute and observant ex- 

 plorer, to purchase stores at exorbitant rates at Unyan- 

 yembc. The necessity for providing for the march of 

 Murphy and Dillon to the coast, with Livingstone's body 

 and most of his followers, is his coinplete justification for 

 incurring this unauthorised expenditure, and there can be 

 no doubt that the Geographical Society will treat its gallant 

 emissary in a generous and liberal spirit. Cameron has 

 suffered cruelly from lever and ophthalmia, and he is now 

 resolutely pressing onwards in the performance of his 

 work — the Society's work — in the face of greater difficul- 

 ties than were encountered by any previous expedition. 

 He carries with him our warmest wishes for his success, 

 and the sympathy of every true geographer in England. 



ON THE NEW RHINOCEROS AT THE 

 ZOOLOGICAL GARDENS 



A GLANCE at our list of additions to the Zoological 

 Gardens during the last week will inform the reader 

 that the Zoological Society has been successful in adding 

 to its already unrivalled collection of specimens of the 

 genus Rhinoceros still another species, which is ex- 

 hibited for the first time in the Society's collection, and 

 most probably in this country. 



It is well known amongst naturalists that in Asia 

 there are to be found two species of Rhinoceros, with a 

 single horn developed on the top of the nose. The 



