Mav ;^o. i<~oy] 



NA TURE 



able to produce gr;iduates who are both willing and able 

 10 widen the bounds of real knowledge. 



The volume containing the studies in pathology is of 

 such merit that the history of its origin deserves a brief 

 mention. In reality, its preparation was commenced five- 

 and-twenty years ago, when Sir Erasmus Wilson wisely 

 presented the University with sufficient funds to establish 

 a chair of pathology — the second created in this country. 

 By a happy inspiration Prof. D. J. Hamilton was asked 

 to occupy it. Out of the raw material provided by the 

 surrounding country Hamilton has raised the school of 

 pathologists which has produced the volume under review, 

 .uid very fittingly dedicated it to him. Tie studies 

 are seventeen in number, and illustrate the diverse 

 directions in which pathology has branched in recent years. 

 To the old pathology — the morbid anatomy of Rokitansky 

 and Virchow — only three of the studies belong, those of 

 Dr. A. Keith, on the malformations of the heart ; 

 Dr. A. Low, on epignathus ; and Dr. G. Duncan, on 

 exophthalmic goitre. Experimental pathology, a recent 

 development, is represented by Prof. A. Cushny's excellent 

 paper on paroxysmal irregularity of the heart, and by 

 Dr. J. J. R. Macleod's study of the condition that follows 

 a direct diversion of the portal blood into the systemic 

 circulation. 



All the other studies, with the exception of that by Prof. 

 St. Clair Symmers on bilharziosis, are concerned with 

 bacteriology — a subject which has expanded into its pre- 

 ■pnt gigantic proportions since Prof. Hamilton went to 

 .\berdeen in 1882. Five of the researches deal with a 

 matter of the very utmost importance — that of immunity. 

 To this group belong the papers by Dr. G. Dean, on 

 plague immunity ; Dr. Wm. Bulloch, on Bacillus 

 pyocyaneus ; Dr. G. G. Macdonald, on pneumococcal in- 

 fection ; Dr. R. D. Keith, on the relationship between 

 haemolysis and phagocytosis of red blood corpuscles ; Dr. 

 J. G. G. Ledingham and Dr. Wm. Bulloch, on the re- 

 lation of leucocytosis to the opsonic content of the blood 

 serum. The question of infection of the body from the 

 alimentary canal is discussed by Prof. Hamilton in con- 

 nection with his investigations of the disease in sheep 

 known as " louping-ill." The bacteria found with this 

 disease are described by Drs. J. M. Adam and B. R. G. 

 Russell. Dr. Wm. Hunter has employed the data he 

 riillected as bacteriologist in Hong Kong to demonstrate 

 that there is a very direct relationship between the 

 epidemics of plague amongst rats and men. The adminis- 

 trative means which may be employed for the prevention 

 of human tuberculosis are discussed by Dr. W. L. 

 Mackenzie ; the results of experiments on the eflficacy of 

 certain disinfectants are given by Dr. A. R. Laing. The 

 manner in which these studies have been edited and 

 arrnnsjed reflects the gr.-atfst credit on Dr. Wm. Bulloch. 



To the quatercentenary publications the Anatomical and 

 Anthropological Society of the University contributed a 

 special volume of its Proceedings. Prof. R. W. Reid, the 

 president of the society, has organised a fully-equipped 

 department of anthropology in the University, with the 

 result that graduates bring back most valuable inforrn- 

 ation regarding the people of the countries or colonies in 

 which they have stayed, and contribute their observations 

 to their old society. In this volume appear five papers 

 which deal with native r.aces. Mr. George Moir writes 

 on the natives of the Malay Archipelago ; Mr. F. S. Max- 

 well contributes notes on Hausaland ; Mr. D. Horn deals 

 • ith the people of the New Hebrides: Captain A. W. C. 

 ■''oung, with the Tibet mission force to Lhnssa : and Dr. 

 R. H. Spittal describes skulls of New Guinea. Important 

 papers on ancient or prehistoric subjects are contributed 

 by Dr. Alex. Low, by Mr. A. Macdonald, and by Dr. J. S. 

 Vlilne. Dr. A. Keith writes on the results of an 

 anthropological investigation of the external ear,_ and Dr. 

 R. J. Gladstone on the variations in shape and size of the 

 skull. The paper on the development of the lower jaw 

 in man, by Dr. .•Mex. Low, deserves especial commenda- 

 tion, both 'for the importance of its facts and for the very 

 f-xact and complete manner in which he has recorded his 

 observations. There is also an excellent paper by Miss 

 A. V. Baxter on 1500 finger-prints which are recorded 

 !n the archives of the anthropological laboratory of the 

 University. 



NO. I96T, VOL. 76] 



THE FLOWERING PLANTS OF THE MESO- 

 ZOIC AGE, IN THE LIGHT OF RECENT 

 DISCOVERIES.' 

 'T'HE subject which I have chosen for my address relates 

 ■'• to plants of Mesozoic or Secondary age, ranging 

 from the Trias, through the Jurassic, to the Cretaceous, 

 the great period which bridges the gulf between the 

 antique vegetation of Paleeozoic days and the essentially 

 modern type of flora which characterises the Tertiary 

 formations. 



We have abundant evidence of the existence of seed- 

 plants in very early days, in fact, practically as far back 

 in the Palajozoic as our records of terrestrial plants extend. 

 On this occasion, however, I am going to speak o.' 

 flowering plants, by which I do not mean the same thing 

 as seed-plants, though the two terms have often been 

 used as synonymous. One of the results of recent dis- 

 coveries in Pal330zoic botany has been to show that the 

 seed-bearing and flower-bearing characters by no means 

 coincide, for the fern-like seed-plants of Pala:ozoic age 

 were in no sense of the words flowering plants. The 

 evidence shows that their seeds, like the fructification of 

 ordinary ferns, were borne on leaves differing but little 

 from the vegetative fronds, and not aggregated on any 

 special axis as are the parts of a flower. The nearest 

 and, indeed, the only analogv to be found among recent 

 seed-plants is in the female plant of Cycas, to which 

 we shall return presently. The Mesozoic plants, however, 

 with which we are now concerned were not only seed- 

 plants, but they bore their reproductive organs in a form 

 which everyone would naturally describe as a flower. 

 They were flowering plants in the full sense of the term, 

 however different in other respects from the flowering 

 plants of the present day. 



The Mesozoic floras from the Upper Trias to the Lower 

 Cretaceous maintain, on the whole, a very uniform 

 character, widely different from that of the preceding 

 Palaiozoic vegetation. True ferns were abundant, more 

 so, no doubt, than in the earlier period ; true conifers, 

 often much resembling recent genera, were a dominant 

 group ; the family now represented by the maidenhair tree 

 (Ginkgo) was prevalent, but the most striking feature 

 of the vegetation was the abundance, in all parts of the 

 world, of plants belonging to the class of the cycads, now 

 so limited a group. 



We will concentrate our attention on the cycad-like 

 plants, or Cycadophyta, to adopt the broader class-name, 

 appropriately suggested by Prof. Nathorst. The living 

 Cycadacea; are, h will be remembered, quite a small 

 family, embracing only nine genera, and, according to a 

 recent estimate, about 100 species, inhabiting the tropical 

 or subtropical regions of both the old and new worlds, 

 but nowhere forming a dominant feature in the vegetation. 

 Throughout the Mesozoic period, however, at least until 

 the Upper Cretaceous is reached, plants with the habit 

 and foliage of cycads are extraordinarily abundant in all 

 regions from which secondary fossils have been obtained ; 

 they are as characteristic of Mesozoic vegetation as the 

 dicotyledons of our recent flora. 



The most important point in questions of affinity is the 

 fructification. Throughout the recent cycads this is of a 

 simple type ; in all the genera the staminate fructification 

 is a cone, consisting of an axis densely beset with scales 

 or sporophylls, each sporophyll bearing on its lower surface 

 a number— often a very large number— of pollen-sacs, 

 grouped, like the sporangia of a fern, in small sori. In 

 eight out of the nine genera the female fructification is 

 also strobiloid, each sporophyll bearing two marginal 

 ovules. In Cvcas itself, however, so far as the female 

 plant is concerned, we find a much more primitive arrange- 

 ment ; no cone at all is difi'erentiated, but the carpels are 

 borne' directly on the main stem of the plant, in rosettes 

 alternating with those of the vegetative leaves. The 

 carpels themselves are lobed and extremely leaf-like,_ bear- 

 ing as many as six ovules in many cases, though m one 

 species the number is reduced to two. Thus in Cycas thr 

 seeds are borne on organs still obviously leaves, and 



■ nuriuKcu..^ .- 1"^- -1 address delivered by Dr. D. H. Scon, 



F R S., before the Royal Microscopical Society on January 16, and pub- 

 lished in the Journal of the Society for April. 



1 Abridged from the prt 



