Dec. 1 6, 1880] 



NATURE 



159 



destitute of chlorophyll. This at least is the mnst prevalent 

 view. Exceptionally, submerged Phanerogams are found with 

 an epidermis destitute of chlorophyll, and there are also some 

 exceptions to the general rule quoted about the leaves of terres- 

 trial Phanerogams. Now it happens that the at present prevail- 

 ino- view is only right in one respect, for up to the present, 

 observations prove the regular appearance of chlorophyll in the 

 outer layer of submerged Phanerogams. The second half of 

 the prevalent view should be completely reversed, for the 

 appearance of chlorophyll in the epidermis of the green organs 

 of Phanerogams is the rule, and with few exceptions The 

 results of Stohr's researches lead to the following : — i. The 

 epidermis of the green organs of the broad-leaved Gymnosperms, 

 and of by far the most of the terrestrial Phanerogams, contains 

 chlorophyll. 2. Chlorophyll appears regularly to be absent 

 fi-om the green organs of the needle-leaved GymnoFperms and 

 the terrestrial Monocotyledons. 3. Chlorophyll is in most cases 

 only to be found in the under surface of the leaves, but is also 

 to be met with in the leaf-petioles and stipules. It remains in 

 such position during the whole life of the organ. 4. Chloro- 

 phyll is seldom to be found in the upper an I lower surfaces of 

 the leaves at the same time. In most cases one can see that the 

 chlorophyll of the cells of the epidermis of the upper surface 

 of the leaf is quickly destroyed upon its formation, by the effect 

 of a too intense light. $. So far as the process of the evolution 

 of the chlorophyll bodies was observed, the latter showed them- 

 selves as starch-chlorophyll bodies. M. Stohr gratefully 

 acknowledges that these investigations were undertaken at the 

 suggestion of Prof. Wiesner, the author of a memoir, " Ueber 

 die natiirlichen Einrichtungen zum Schutze des Chlorophylls der 

 lebenden Pflanze." The leaves of nearly one hundred species of 

 plants were carefully examined, and full details of these examin- 

 ations are given in the tables that accompany M. Stohr's 

 memoir. The investigations were carried out in the botanical- 

 physiological laboratory of the University of Vienna. {Silzungs- 

 bcridtU d. h. Akad. Wisseitschaften — mathem.-naturw. CI., 79 

 Ed., S. 87.) 



Blood-Vessels of Valves of the Heart. — Recent re- 

 searches by Dr. Langer (Vienna Acad. Anz.) prove that several 

 mammalian genera (pig, dog, bullock) have a fully-formed blood- 

 vascular system both in the semilunar and tlie atrioventricular 

 valves. On the other hand an examination of about 100 human 

 hearts (of children and adults) discovered blood-vessels in the 

 heart-valves only in one case, that of a woman of sixty, in 

 whom they were evidently the result of a pathological process. 

 Dr. Langer explains the difference by a difference in the mode of 

 formation of the valves. 



Light and the Transpiration of Plants. — Dr. Comes 

 (Naples Academy) finds, inter ali,i, that light favours transpira- 

 tion ; that a little after midday transpiration is at its maximum ; 

 that, other things equal, that organ transpires most which is most 

 intensely coloured, and it emits most water when exposed to that 

 part of the solar spectrum where it absorbs most light ; and that 

 only those luminous rajs which are absorbed favour transpiration 

 of an organ (not the inactive rays) ; so the transpiration is mini- 

 mum under the rays coinciding in colour with that of the organ, 

 and maximum under the complementaiy rays. 



PiNGUlCULA Alpin.\. — Prof. Klein of Buda-Pesth publishes 

 in the la-t part of Cohn's Bdtvcige zur Biologie der Pflanzen an 

 interesting memoir on this plant, i. It appears in two forms : one 

 has bright green leaves ; the other has more or less reddish- 

 brown coloured ones. These forms however appear only to pos- 

 sess the value of local varieties. 2. Piiigiiiciila alpina is, like the 

 other species of Pinguicula, an insectivorous, i.e. flesh-eating 

 plant, but is partly also a plant-eating one. 3. Its roots are 

 simple, i.e. they do not branch, and they possess notwithstanding 

 a pericambium. The cells of the bast layer have handsome, for 

 the most part doubly-ridged longitudinal walls, and are the first 

 formations that differ from tlie primary meristem of the end of 

 the root. The greatest part of the root remains in respect to 

 the tissue formation in an undeveloped and almost embryonic 

 condition. 4. The caulome contains between the pith and bark a 

 vascular ring which is characterised by very short-jointed vessels : 

 these joints are bound together at tlie points of contact, and 

 their cross walls are broken through by one single circular opening. 

 The bundles of vessels belonging to the roots spring partly out of 

 the caulomic vascular ring, partly out of the leaf spur. 5. The 

 original bending in of the edges of the leaves can be regarded as 

 an advantageous arrangement in respect to the catching of insects. 



as insects cannot easily get over the edge of the leaf, and can 

 therefore also be generally caught under it. 6. The cells of the 

 epidermis of the leaf contain no chlorophyll, but the green-leaved 

 specimens contain a colourless sap and the red-leaved ones a 

 reddish sap. Be-ides they always possess a cell nucleu- in which 

 crystalloids are to be found. 7. The edge of the leaf is trans- 

 parent, and consists of a single row of epidermis cells. 8. The 

 epidermis of the leaves contains as well on the upper as on the lower 

 side tolerably numerous stomates, which are only wanting on the 

 outermost edge. Their manner of formation corresponds mostly 

 to that observed in Thymus ; it shows however some devia- 

 tions. The stomate is surrounded by a narrow edging which is 

 more sti'ongly cuticularised than the outer walls of the epidermis 

 cells. The cells of the stomates contain no crystalloids, but oiJy 

 a few very small chlorophyll bodies. 9. The epidermis of the 

 upper surface develops two kinds of glands with and without 

 stalks. The glands witli stalfa consist of a basal cell projecting 

 above the epidermis ; out of this proceeds a one to four-celled 

 half spherical columella, on the top of which a glandular body, 

 consisting of a layer of radially-placed cells, is placed cap-like ; the 

 stalkless glands are similarly built, only the stalk is wanting, the 

 columella is conical, and the glandular body does not as a rule 

 project more than half over the epidermis. The process of de- 

 velopment is similar in both glands. lo. Stalkless glands 

 appear also on the lower side of the leaf. They are only 

 feebly developed, and their cap portion hardly projects over the 

 epidermis. From their presence it can be deduced that the 

 various kinds of Pinguicula once only possessed stalkless glands ; 

 from which in process of time both the stronger developed stalk- 

 less glands and those also with stalks became developed on the 

 upper side of the leaf, by which the capacity of the leaves for 

 catching and digesting insects was at the same time perfected. 

 In connection with this, one can infer a somewhat similar theory 

 about Utricularia and Aldrovanda, and even about Diona:a 

 and Drosera. II. The bundles of vessels belonging to the leaves 

 are branched out in netlike veins, and anastomose chiefly with 

 one another. The veins at the ends unite near the edge of the 

 leaf into a sympodial layer, from which numerous veins go out 

 directed to the edge of the leaf and end in enlarged spirally 

 thickened cells, which cells sometimes border directly on the 

 epidermis cells belonging to the edge of the leaf or are separated 

 from them by one or more cells. 12. The tracheal vessels of the 

 leaves, as ^^ell as of the other parts of Piiiguieula alpina 

 never contain air, but either a watery fluid or a yellowish- 

 brown resinous-looking substance. This circumstance, together 

 with the strange branching of the tracheal vessels in the edge of 

 the leaf particularly adapted to catching insects seem to prove 

 (or show) that the tracheal vessels serve for the transport of a 

 substance that stands perhaps in direct connection with the 

 function of the leaves. 13. The mcsophyll cells form among one 

 another tolerably large interstices filled with air, and contain 

 generally chlorophyll bodies in abundance. 14. Starch is to te 

 foand in the chlorophyll bodies of P. alpina, and also in the 

 small stems and roots of the hybernating plants, when it appears 

 in small compressed nuclei. 15. Glands with and without stalks 

 appear in the flower stalks as well as in the flowering parts. 



GEOGRAPHICAL NOTES 

 At a meeting of the Geographical Society on Monday evening 

 Capt. T. II, Iloldich, R.E., of the Survey of India, read a very 

 interesting paper on the geographical results of the Afghan 

 campaign, in which, after giving a sketch of the features of the 

 country^ he summed up the additions lately made to our know- 

 ledge. These are very considerable, for in the last two or three 

 years 'he and Major Woodthorpe with their staff have surveyed 

 and mapped from 25,000 to 30,000 square miles of country. 

 Some of the more important facts ascertained are the facility 

 with which practicable roads can be made through the passes of 

 Afghanistan, and the comparatively low elevation of those of 

 the Hindu Rush, which, according to Capt. Iloldich's view, 

 would offer no real barrier to the advance of a properly-equipped 

 army. Capt. Holdich hinted that the further mapping and 

 survey of the country were being continued by native explorers 

 attached to the Survey of India, and he thought that in a few 

 years' time it would be known from end to end, and that our surveys 

 would then join on to those of the Russians north of the Hindu 

 Rush. Capt. Holdich remarked also on the curious inter- 

 mingling of races in some parts of Afghanistan, and in the 

 ennun" discussion Mr. Blanford, late Director of the Geological 



