Max 22, 1884.J 



NA TURE 



79 



phototype. This process does not fade as a photograph 

 is liable to do, but has the consistency of print with the 

 appearance of a steel engraving. By an ingenious method 

 adopted by the author only one side of the bird's skeleton 

 is given in the plate, and thus the confusion which is 

 often seen in osteological illustrations from the appear- 

 ance of the opposite side of the skeleton in the picture is 

 obviated. The plates, which have been executed in 

 Dresden at Mr. Wilhelm Hoffmann's Art Institute, de- 

 serve great credit for their execution. The letterpress 

 which accompanies the figures gives the distinguishing 

 characters of the skeletons with their principal measure- 

 ments. 



It is proposed to issue at least two parts in the course 

 of every year, each part to contain ten plates. Out of 

 the number hitheno published we find illustrations of 

 seventeen Parrots belonging to fourteen genera, amongst 

 them being the rare Dasyptilus pesqueti from New 

 Guinea, the smallest known Parrot, Nasiierna pygmaa, 

 as well as the largest one, Microglossus aterrimus, both of 

 which are from New Guinea ; Nestor meridionalis and 

 Stringops habroptilus from New Zealand, besides illustra- 

 tions of members of the following genera : — Eclectus, 

 Cacatua, Cyclopsitta, Loriat/ns, Trichoglossus, Charmo- 

 syna, Brotogerys, Tanygnalkus, and Eos. Of Birds of 

 Paradise illustrations are given of Cicintvurus regius, Para- 

 disco minor, Manucodia chalybeata with us twisted 

 windpipe, along with those of its allies. Other Birds of 

 Paradise are promised by Dr. Meyer. Among the 

 Pigeons are figured species of Carpophaga, Otidiphaps, 

 CEdirhinus and Ptilopiis, side by side with skeletons and 

 skulls of some of the domestic races. Of Kingfishers 

 figures of the skeletons of the genera Cittura, Tanysiptera, 

 and Sauromarptis are furnished, and among others we 

 find illustrations of such interesting genera as the follow- 

 ing:— Pelenopides, Meropogon, CoUocalia, Heteralocha, 

 Rallina, Scissirosh inn, Slreptocitta, Oriolus, Dicrurus, 

 Lepidogrammus, &c. 



We must draw the special attention of our readers to 

 the skeleton of a species of Notornis from New Zealand, 

 which Dr. Me\erhas figured in Plates 34 to 37. This 

 skeleton was procured along with the skin of the bird in 

 South Island, N.Z., in the year 1S79, and has found its 

 way to the Dresden Museum. Complete figures of the 

 osteology of this interesting genus are here given for the 

 first time. Our national collection contains two skins of 

 Notornis, but no skeleton, only some fossil remains from 

 the North Island having been described and figured in 

 the year 1848 by Prof. Owen. From a comparison of 

 the latter with the skeleton now in the Dresden Museum, 

 Dr. Meyer has been induced to consider that the North 

 Island species is distinct from that inhabiting the South 

 Island, and as the name of Notornis mantetti was given 

 by Owen to the former bird, the specimen in the British 

 Museum which came from the South Island must bear 

 the name of Notornis hochstetteri, as Dr. Meyer proposes 

 to attach to it the name of the well-known New Zealand 

 explorer, Prof, von Hochstetter of Vienna. 



A comparison is instituted by Dr. Meyer between the 

 skeletons of different species of Porphyrio and Ocydro- 

 mus. Together with the skeleton of the Jungle-fowl 

 (Callus bankiva), which Dr. Meyer himself brought from 

 Sangi Island, north of Celebes, and different species of 

 grouse (amongst them that of Tetrao medius), we find 

 representations of the skeletons of several domesticated 

 races of fowls. The importance of the characters pre- 

 sented by the differences of the crania and other portions 

 of the skeletons of domestic fowls and pigeons was long 

 ago proved by Mr. Darwin, and as there were only 

 certain portions of the skeletons figured by him, the 

 material which Dr. Meyer has collected with great care 

 offers to the student a better opportunity of going deeply 

 into this subject. 



R. B. S. 



THE " POTETOMETRE," AN INSTRUMENT 

 FOR MEASURING THE TRANSPIRATION 

 OF WATER BY PLANTS 



IN view of the interest now attaching to recent advances 

 in vegetable physiology, it seems not unlikely that a 

 description of the instrument bearing the above name, 

 lately published by Moll (Arckivis Nierlandaises, t. xviii.), 

 will serve a useful purpose. 1 The apparatus was designed 

 to do away with certain sources of error in Sachs's older 

 form of the instrument, described in his " Experimental- 

 Physiologic " — errors chiefly due to the continual alteration 

 of pressure during the progress of the experiment. 



As shown in the diagram, the " potetometre " consists 

 essentially of a glass tube, a d, open at both ends, and 

 blown out into a bulb near the lower end ; an aperture also 



Fig. 1 



exists on either side of the bulb at or about us equator. 

 The two ends of the main tube are governed by the stop- 

 cocks a and d, and the greater length of the tube is 

 graduated. A perforated caoutchouc stopper is fitted into 

 one aperture of the bulb e, and a tube, g/i, fits hermeti- 

 cally to the other. This latter tube is dilated into a cup 

 at k to receive the caoutchouc stopper, into which the end 

 of the shoot to be experimented upon is properly fixed. 



The fixing of the shoot is effected by caoutchouc and 

 wire or silk, as shown at i, and must be performed so that 

 the clean-cut end of the shoot is exactly at the level of a 

 tube passing through the perforated stopper, <•, of the 

 bulb ; this is easily managed, and is provided for by the 

 bending of the tube gh. The tube /, passing- horizontally 

 through the caoutchouc stopper e, is intended to admit 

 bubbles of air, and so equalise the pressure and at the 

 same time afford a means of measuring the rapidity of the 

 absorption of water by the transpiring shoot. This tube 



1 Especially also with reference to M>. F. D.- ruin's dtscr'ptbn of his 

 own ingenious instrttr.ent (see Nat I RE, M v -, p. 7>- 



