

NA rURE 



[August 3, 189; 



was reflected from the surface of a prism into a dark room, and 

 again diminished in intensity by placing in its path rotating 

 sectors with very narrow apertures. 



Near mid-day on July 8 the sun was very clear, the sky being 

 free from clouds, and a strongish wind blowing from the west. 

 Two separate sets of measures were made with an interval of an 

 hour between each. It was found that the dominant colour was 

 X4885 in both cases, and in the first set it was diluted with 

 5'45 of white, and in the other with 5 '14 of white. This indi- 

 cates that sun light contains slightly more green-blue rays than 

 the light emitted from the crater of the positive pole of the 

 electric light. This agrees with the spectrum measures made 

 in "Colour Photometry. " 



Cloud light was next matched on days in which the sky was 

 overcast. A comparison of the general light of the zenith was 

 all that was attempted, and near mid-day. 



It was found that it required i part of K 4864 diluted with 

 5 "5 parts of white to make a match. It will be seen that the 

 dominant colour of cloud light lies between that of the sky and 

 of the sun, as might be expected, and is decidedly whiter than 

 the sky, as might also be anticipated. 



Various comparisons of sunset colours have been made, and 

 found to range from A. 6300 up to A. 4800 ; in some cases it was 

 necessary to match by means of complementary colours. 



The light from a paraffin candle it was found could be very 

 closely matched with D sodium light. The equation may be 

 expressed as follows : — 



Candle light = \ 5880 + 0-4W. 



The amount of added white varied from 01 to 0'5, and it is 

 in this part of the spectrum that a large number of separate 

 observations are required in order to get a good and fairly trust- 

 worthy mean. 



June 15. — "Some of the Effects and Chemical Changes of 

 Sugar injected into a Vein." By Vaughan Harley, M.D., 

 Teacher of Chemical Pathology, University College, London, 

 and Grocer Research Scholar. Communicated by George 

 Harley, M.D., F.R.S. 



When 10 grams of grape-sugar per kilo, of body-weight of a 

 dog are injected into a vein and elimination by the kidneys pre- 

 vented, the sugar so rapidly disappears from the circulating 

 blood that it reached the normal quantity within six hours. 

 The quantity of glycogen in the liver and muscles is not 

 markedly increased. 



The amount of lactic acid in the blood is increased to so 

 marked a degree as in some cases to be more than the quantity 

 of sugar. The greatest amount of lactic acid is found in the 

 liver. Alcohol, acetose, and aceto-acetic acid are also present 

 in the blood after the introduction of the sugar. There is no 

 increase in the quantity of ammonia in the blood. 



The introduction of the sugar causes marked disturbance of 

 the nervous system, shown by the appearance of muscular 

 spasms, hurried breathing, and finally coma. These are 

 probably due to some of the products derived from the break- 

 ing down of the sugar molecules acting as a poison, which by 

 further breaking up into other substances become harmless and 

 the animals recover. 



" Studies in the Morphology of Spore-producing Members. 

 Part I. Equisetinen: and Lycopodinese." By F. O. Bower, 

 D.Sc, F.R.S. , Regius Professor of Botany in the University 

 of Glasgow. 



The first pages are devoted to the discussion of points of 

 general morphology of the sporophyte, as it is seen in arche- 

 goniate plants, together with a sketch of the history of opinion 

 as to the morphological "dignity" of the sporangia, and their 

 relation to the parts (usually sporophylls) which bear them. The 

 position of Goebel is adopted, that sporangia are as much organs, 

 sui generis, as are shoots, roots, &c., no matter where they may 

 be seated. 



It is customary to assume that the ontogeny will serve 

 as a guide to the history of descent in plants as in animals. 

 As applied in detail to the sporophyte generation this assumption 

 cannot be upheld : for the conclusions drawn from wide com- 

 parison would be directly antagonistic to such a history. The 

 young sporophyte of a fern first forms foliage leaves, stem, and 

 roots ; only after a considerable period are sporangia produced. 

 On the recapitulation theory it would be concluded from this 

 that the vegetative system was the first to appear, while 



NO. 1240, VOL. 48] 



sporangia were of subsequent origin, and it might further be 

 held that sporophylls are metamorphosed foliage leaves. But 

 the whole comparative study of the sporophyte of lower forms 

 leads to the opposite conclusion ; spore-production was the first 

 office of the sporophyte, and if the lower Bryophyta really illus- 

 trate the mode of origin of the sporophyte, the production of 

 spores preceded the existence of a vegetative system of the 

 sporophyte, and has apparently been a constantly recurring event 

 throughout evolution. It must therefore be concluded that the 

 history of the ontogeny does not truly recapitulate the history of 

 the descent as regards the neutral generation ; the sporophyte 

 is, in fact, an intercalated phase which has acquired vegetative 

 characters. Comparative study of the Bryophyta leads to the 

 conclusion that the whole vegetative region was the result of 

 progressive sterilisation of potentially sporogenous tissues. 



A brief review of the progress of this sterilisation as it has 

 already been recognised among the Bryophyta is next given ; it 

 is pointed out that (a) the sterilisation may involve the whole 

 thickness of the sporophyte, as in the formation of the seta, or 

 (I) it may make itself apparent only in individual cells of the 

 sporogonial head (elaters). But the Bryophyta are clearly 

 marked from vascular plants by two characters : (i) the absence 

 of appendicular organs ; (2) the single continuous archesporium. 



There are, at least, three possible ways in which plans with 

 numerous separate archesporia may have originated from plants 

 of some Bryophytic type: (i) by branching (chorisif) of a 

 sporogonial head ; (2) by formation of entirely new archc:sporia, 

 having no direct connection by descent from pre-existent ones ; 

 (3) by partitioning of a continuous archesporium. 



The frequent presence of synangia in eusporangiate Vascular 

 Cryptogams suggests either coalescence accompanying reduction 

 in a descending series, or partitioning by means of septa in an 

 ascending series ; the first question in connection with such 

 synangia will be whether in any natural sequence of Vascular 

 Cryptogams the progression from a non-septate to a septate 

 condition can be traced ; or the converse. Though the facts 

 at hand do not amount to an actual demonstration, the Lyco- 

 podineae and their allies are believed to be an ascending series, 

 and they are seen to supply important evidence. Phylloglossiim, 

 Lycopodium, and Selaginella, Lepidodendron, and the Psilotacejt 

 show natural affinities. To this series Isoetes may be added. 



As regards the sporangia, there can be no doubt of the 

 homology of the sporangium of Phylloglossum, Lycopodium, 

 Selaginella, and Lepidodendron. Within the genus Lycopodium 

 differences of detail have been observed analogous 10 sudl 

 differences as would result in the production of mor^: bullCT 

 sporangia, such as those of Lepidodendron and Isoetes, though 

 it is true these differences are not so extensive. Ii these 

 very large sporangia trabeculse are found, as rods or plates of 

 sterile tissue, which may project far upwards into the sporangial 

 cavity {Lepidodendron), or may extend the whole way through 

 it to the upper wall (Isoetes). In the latter case it has be«l 

 shown by Goebel that the trabeculse are the result of differenti- 

 ation of a potential archesporium, part of which is sterilised and 

 forms the trabecular. 



The next step is to the Psilotacese ; and the first question is 

 that of the real nature of the synangium in these plants. 

 Sections both of Psilotum and Tmesipteris, show the synangium 

 to originate below the apex of the sporangiophore, and from its 

 upper surface, in a manner very similar to the sporangium of 

 Isoetes. The form of the young synangium resembles that of 

 the sporangium of Lepidodendron, with which genus also there 

 is extraordinary anatomical similarity. The septum is similar 

 in its origin to the sporogenous masses, and is not at first dis- 

 tinguishable from them ; in this respect it also resembles /f^to- 

 It would thus appear that the whole .synangium is comparable 

 in origin and position, in the broad lines of development, and 

 in function to the sporangia of other Lycopods, that is, a septate 

 comparable with a non-septate body. 



Tmesipteris appears to be a variable plant as regards the form 

 and structure of its synangia ; there is, however, some method 

 in its irregularities ; smaller synangia of simpler form and 

 structure are found at the limits of its fertile zones, while aboutl 

 the middle of it synangia have been found with three locoh,j 

 corresponding to those of Psilotum. Examination of those 

 of simpler form shows that they may be only partially septate, or 

 the septum may be absent from the first. I have been able toj 

 prove in young synangia of this type that the tissue -which woulo\ 

 normally form the septum may he sporogenous ; this is exactl)i 

 the converse of what has been proved by Goebel in Isoetes, anC| 



