NA TURE 



55 



THURSDAY, SEPTEMBER 17, 1914. 



THE CRETACEOUS FLORA, 

 Catalogue of the Mesozoic Plants in the British 

 Museum [Natwral History). The Cretaceous 

 Flora. Part i., Bibliography, Algae and Fungi. 

 By Dr. Marie C. Stopes. Pp. xxiii + 285+11 

 plates. (London : British Museum (Natural 

 History): Longmans, Green and Co., 1913.) 

 Price 125. 



DR. MARIE STOPES set herself a severe task 

 in deciding to include in the catalogue of 

 Cretaceous plants an exhaustive bibliography and 

 list of species. The list of species from Cretace- 

 ous beds, described up to December 31, 1910, 

 occupying nearly two hundred pages, affords a 

 striking illustration of the large amount of 

 material in palaeobotanical literature that serves 

 no useful purpose. While acknowledging that a 

 list of this kind is valuable as a source of informa- 

 tion, it is difficult to repress a certain suspicion 

 that the result obtained is scarcely a fair return 

 tor the labour expended. As Dr. Stopes continues 

 her investigations the value of the list will be 

 considerably increased by the addition of critical 

 remarks on such of the records as come under her 

 purview. As it stands the catalogue of names 

 may mislead the unwary who have not learnt by 

 experience to regard with distrust a large propor- 

 tion of determinations based on fragments of fossil 

 Angiosperms; but as a storehouse of biblio- 

 graphical information the list will be of real ser- 

 vice to students. In the Introduction Dr. Stopes 

 tfives a useful summary of literature dealing with 

 Cretaceous floras, and the stratigraphical table 

 is a particularly welcome contribution which will 

 do much to clear up the confusion caused by the 

 adoption of different terms for subdivisions of the 

 Cretaceous system in different countries. The 

 publication of a list of dates of the parts of 

 Brongniart's " Histoire des vegetaux fossiles " 

 is a much needed step towards a greater uni- 

 formity in systematic work : in the preparation 

 of this bibliographical note the author expresses 

 her indebtedness to Mr. C. Davies Sherborn. 



The latter part of the catalogue is concerned 

 with descriptions of Cretaceous thallophyta, in 

 many instances accompanied by helpful illustra- 

 tions. The author restricts the use of the generic 

 name Algites, proposed in 1894 in a comprehen- 

 sive sense for fossils which cannot be referred 

 with any degree of certainty to a particular recent 

 genus or family, to flattened impressions, and em- 

 ploys Sternberg's designation Chondrites for 

 "algae, or fossils which suggest algae, with a 

 NO. 2342, VOL. 94] 



much-branched dichotomous or sympodial thallus 

 which is cylindrical." Having regard to the 

 worthlessness, from the point of view of relation- 

 ship to Chondrus, of most of the fossils referred 

 to Chondrites, it would seem preferable to dis- 

 card the name in favour of a general designation 

 such as Algites if used in the wider sense in 

 which it was first proposed. The concise sum- 

 mary of the characters of several types of algae 

 belonging to the Siphonaceae -and the Rhodo- 

 phyceae will serve to direct attention to the possi- 

 bilities of a neglected branch of palaeobotanical 

 research. Among the fungi included in the 

 catalogue the two most interesting are the 

 Japanese species, Pleosporites shirainus and 

 Petrosphaeria japonica, the former being repre- 

 sented both by perithecia and septate vegetative 

 hyphae. 



Dr. Stopes carries into practice her suggestion 

 {Annals of Botany, 191 1) that "all fossil plants 

 for which there is no good, scientific reason for 

 association with given families and genera, and 

 to which, nevertheless, names indicative of such 

 affinities have been given, should be printed hence- 

 forth in Gothic characters." If this plan were 

 adopted in the list of Cretaceous species in the 

 first part of the volume as well as in the descrip- 

 tive portion, very serious demands would be made 

 on the printer's Gothic fount. It is doubtful 

 whether this method will find favour : the use by 

 palaeobotanical writers of designations implying 

 affinities that are assumed on wholly insufficient 

 grounds seriously detracts from the value of pub- 

 lished lists; but, it may be urged, the better 

 course would be to discard the misleading names 

 rather than to dignify them by the employment 

 of Gothic letters. Moreover, this attempt to in- 

 stitute an Index Expurgatorius is based on an 

 individual opinion and has not the sanction of 

 supreme authority. 



Dr Stopes has made an excellent beginning : 

 the less interesting and more laborious work has 

 been accomplished, and we confidently expect 

 that the later volumes will add greatly to our 

 knowledge of the vegetation of a period which 

 is of exceptional importance. The flora of the 

 preceding Wealden period is, in its general facies, 

 a continuation of the Jurassic floras : flowering 

 plants had undoubtedly been evolved, but they 

 occupied a subordinate position and, so far as we 

 know, were unrepresented in the Wealden flora 

 of Britain. It was in the succeeding stages 

 of the Cretaceous system that this remarkably 

 successful group rapidly rose to the position of 

 dominance that it now occupies in the floras of 

 the world. 



A. C. Seward. 



