532 



NATURE 



\Oct. 21, 1875 



scalpels, forceps, and scissors, being nearly all that is 

 essential to a biological laboratory. These can be pro- 

 cured by anyone ; and the student when thus equipped 

 with Huxley and Martin's " Practical Biology " in his 

 hands, need only look around for some of the most 

 easily obtainable animals, upon getting which he can 

 start work in good earnest. 



In the descriptive portion of the work there is one 

 point to which we cannot help referring, which is in con- 

 nection with the circulation of the blood. It is an expla- 

 nation, originally given by Briicke, we believe, of the 

 manner in which the mixed arterial and venous blood in 

 the single ventricle of the frog is distributed in such a 

 manner that the venous blood mostly enters the lungs. " It 

 fills (during the systole) the'^conus^arteriosus, and, finding 

 least resistance in the short and wide pulmonary vessels, 

 passes along the left side of the median valve into them. 

 But as they become distended and less resistance is offered 

 elsewhere, the next portion passes on the light side of the 

 longitudinal valve into the aortic arches," The words 

 italicised by us are those which it is difficult to compre- 

 hend, for it is evident that if the pulmonary artery offers 

 less resistance at the commencement of the systole, it 

 will do so all through the revolution in proportion to the 

 relative calibre of its capillaries and those of the system 

 generally ; and then there is no reason why the valve 

 should flap back. 



OUR BOOK SHELF 



Rolotnahana, and the Boiling Springs of New Zealand. 

 A Photographic Series of Sixteen Views, by D. L. 

 Mundy. With descriptive notes by Ferdinand von 

 Hochstetter, Professor of the Polytechnic Institution of 

 A'^ienna. (London : Sampson Low and Co., 1875.) 



The autotype illustrations which form the main feature 

 of this handsome volume are triumphs of the photo- 

 graphic art, and reflect the highest credit upon their 

 author, Mr. Mundy. The photographs are on a scale 

 quite large enough to give one a satisfactory idea of the 

 main features of the various scenes intended to be por- 

 trayed ; and by the judicious introduction into most of 

 the views of the human figure, a good idea of the scale of 

 the photographs is at once afforded. 



The remarkable region illustrated by Mr. Mundy's 

 series of photographs lies just about the centre of the 

 North Island of New Zealand, in the south of the pro- 

 vince of Auckland. The culminating or rather origi- 

 nating point of the phenomena described. Prof. Hoch- 

 stetter regards as the still active volcano Tongariro, in 

 the north of the province of Wellington. From this 

 volcano three lines of volcanic action are supposed to 

 proceed in a north-easterly direction by Lake Taupo to 

 Lakes Rotorua, Rotoiti, and Rotomahana respectively, the 

 last-mentioned line proceeding inwards as far as the marine 

 volcano Whakari, in the Bay of Plenty; this line also, 

 near its source, includes the hot springs at the head of 

 Lake Taupo, about forty miles to the north of Ton- 

 gariro. Another line, which follows to some length the 

 outflow of the river Waikato'from Lake Taupo, is marked 

 by the hot springs and steam jets of Otumaheke and 

 Orakeikorako, on the river's banks, and those of the 

 Pairoa mountain range. The third line of action forming 

 eruptions of this kind is exhibited in the hot springs of 

 Rotorua and the solfataras of Rotoiti, which terminate 

 these specimens of volcanic action on land, being situated 

 near the sea- coast. While all along these three lines 

 evidences of volcanic action are visible in the shape of 

 hot springs, solfataras, geysers, mud-lakes, &c., the chief 



interest centres in Rotomahana, where the most beautiful 

 and marvellous effects of this action are displayed. 

 Though on a much smaller scale, the phenomena greatly 

 resemble those which are seen in such profusion in the 

 Yellowstone region of North America. 



Mr. Mundy devotes most of his photographic views to 

 the illustration of the phenomena to be witnessed in and 

 around Rotomahana. This is one of the smallest lakes in 

 the region, being scarcely a mile in length and a quarter 

 of a mile in breadth ; it is 1,088 feet above the sea, and 

 the temperature of the lake itself varies from 60° to 100'' 

 Fahr. On the margin of the lake are many boiling springs, 

 and around it are a great variety of phenomena similar 

 to those which are witnessed in Iceland and in North 

 America. It is impossible in a few words to give any 

 adequate idea of these phenomena, and we must there- 

 fore refer our readers to Mr. Mundy's beautiful illustra- 

 tions, and Prof. Hochstetter's brief but clear descriptions. 

 One of the photographs gives a fine view of Lake Rotorua, 

 about twelve miles north of Rotomahana, and the last 

 four are devoted to the illustration of Lake Taupo and the 

 phenomena to be seen in its neighbourhood. Roto- 

 mahana, we may state, is about forty- five miles N.N.E. of 

 Lake Taupo, and about double that distance from Mount 

 Tongariro. 



Lake Taupo lies at 'a height of 1,250 feet above the 

 sea, and no bottom has been found at-a depth of 200 

 fathoms. Prof. Hochstetter conjectures that its waters, 

 which have only one visible outlet, the Waikato, but many 

 tributary streams, has a subterranean outlet to the north. 

 It is this, he believes, which gives rise to the curious phe- 

 nomena which abound in the region to which Mr. Mundy's 

 photographs refer ; the water, after being heated by under- 

 ground volcanic fires, generates high-pressure steam that 

 forces its way to the surface, bearing the characteristics 

 of the rocks v/ith which it has come into contact : the 

 New Zealand springs, we should say, are divided into two 

 distinct classes, the one alkaline, 'and the other acid. 

 Whatever may be the value of Prof. Hochstetter's expla- 

 nation of the phenomena, there is no doubt about the 

 value of Mr. Mundy's illustrations of a district which 

 seems to be all that now remains of a once extensive 

 active volcanic region. While as a collection of well- 

 executed views of great interest the work deserves a wide 

 circulation, to the student of geology it is of great value, 

 as affording a far more satisfactory idea of an important 

 feature of the physical geography of New Zealand than 

 any mere description can convey. 



Elementary Lessons in Botanical Geography. By J. G. 

 Baker, F.L.S., Assistant Curator of the Herbarium at 

 Kew. (London : L. Reeve and Co., 1875.) 



A WANT has long been felt of a small text-book for the use 

 of lecturers and students dealing with the distribution of 

 plants on the face of the globe. A work of this kind neces- 

 sarily contains a large amount of detail and a formidable 

 anay of plant-names. These features of the present little 

 volume are less objectionable when its special purpose is 

 borne in mind, viz., the instruction of gardeners ; the 

 various chapters into which it is divided being in fact the 

 substance of a series of lectures delivered to the gardeners 

 at Kew. A reference to these details would be out cf 

 place in a short notice ; and the best idea will be con- 

 veyed by giving the author's final summing up, viz : — That 

 each species has originated from a single centre ; that 

 species have originated in different parts of the world, 

 and that the flora of any given tract depends largely on 

 its geographical position ; that a large portion of the 

 present genera (or types which agree in structure down 

 to minute detail) were in existence before the end of the 

 Secondary period, and have passed through the very great 

 changes in climate and the relative positions of sea and 

 land that have occurred during the Tertiary period ; and 

 that species (or types which accord not in structure only. 



