25- 



NA TURE 



'{Jan. 13, 1 88 1 



each segment. They have the venation, bilobation, and 

 petiole of Ginlcgo, yet approaching in their larger leaves 

 to Baieria. Other similar species (?) diminishing in size 

 are G. schinidtiana, with about six segments, G.flahcllata, 

 with fourteen or fifteen segments, and G.pitsilla, with a less 

 number, and barely an inch across the base. These three 

 might probably be united into a single species. The 

 remaining form from Siberia, G. htil/oiu, is less divided, 

 having but four rounded segments, and is in that respect 

 a nearer approach to the existing one. 



The nearest, however, is G. i/ii^i/ala from the Jurassic 

 of Spitzbergen, which, but for smaller size and thicker 

 petiole, might be placed in the existing species. Leaves 

 fro-Ti Scarborough, said to be of the same species, are 

 larger. G. iiitegriiiscula is evidently the smaller and less 

 lobate leaf of the same species, and the author has besides 

 ta'^en the unnecessary care to establish five duly named 

 and lettered varieties, thus clearly showing that he had 

 formed no adequate conception of the extent to which the 

 leaves of the existing tree may vary, even on the same 

 branch. His species should be reduced, the excessive 

 subdivision being a disadvantage and rendering the work 

 unwieldy. The author also changes the classification of 

 the Coniferce between the second and third volumes, and 

 the name for this genus between the third and fourth 

 volume;, without explanation or notice, which, in a work 

 addressed especially to geologists, is an inconvenience. 



The third genus, Baieria, possesses a larger and more 

 palm like leaf, averaging nearly five inches in radius, 

 primarily bilobed, each 1 jbe forking either once or twice, 

 the ultimate seginents being of unifonii width and pos- 

 sessing four parallel veins each. The leaf tapers to the 

 petiole, which is not preserved in the engraved specimens. 

 The bilobation and venation connect it sufficiently with 

 Ginkgo, and the persistence of these characters through- 

 out the whole group, which would hardly have been 

 suspected to have a morphologic value, is peculiarly 

 remarkable. 



There is a marked diminution in the group in the 

 Cretaceous. Baieria from the Komeschichten is limited 

 to vestiges of stunted form placed among the ferns, while 

 Ginkgo appears in a starved species with small leaves 

 and short thick petiole, described as AdiantiDii for- 

 }/wsi/ 7t, and by fragments from the Upper Cretaceous 

 Ataneschichten, inappropriately named G. primordialis. 



In the Arctic Eocenes (Miocene; of Heer) Gmkgo has 

 only, and that very sparingly, been met with in Green- 

 land. Tnis variety so resembled G. adiantoid-es of the 

 Italian Miocenes, that Heer almost directly abandoned 

 his specific name piiniordialis, and became doubtful 

 even whether both should not be united with the existing 

 species. 



The small fragments figured in the Miocene Baltic flora 

 ate inconclusive, and we only again meet with it in the 

 Miocenes as far south as Italy, the South of France, and 

 the Mississippi.' It has been said to occur in English 

 Eocenes by Heer, who wrote upon the tracing of an 

 Adiantum from Bournemouth, " this is a Ginkgo," and 

 by Ettingshausen, who considers four seeds from Sheppey 

 to belong to it, akhough less than half the size of those 

 of the present Gin'cgo, and rather materially differing. 

 Its abse.ice otherwise in British and in French Eocenes, 

 and in the Swiss and Austrian Tertiaries, is ascertained, 

 for the occurrence of so distinctly-marked and easily- 

 preserved a leaf could not well be overlooked. 



The very strongly-mirked and exceptional characters 

 of Ginkgo, shared by the allied extinct genera, the remote- 

 ness of its origin in the Carboniferous, its extensive de- 

 velopment in the Mesozoic, and persistence through so 

 many ages, seems to render it desirable to separate them 

 from the Taxea; into a distinct tribe. Already dying out in 

 the Cretaceous and lingering through the Tertiaries in a 

 single species, its existence noiv is a mere survival. 



* Since writing theabcvc. Sapjrt.l inf .-rmsme that the supposed Miss'.ssippi 

 specie, is really a Lygodium. 



Its hone has been from time to time within the Arctic 

 circle, yet it is scarcely proved, as Saporta says, that it 

 actually originated there. The leaf of G. dii;ilata from 

 the Scarborough oolite, figured by Schimper, is far larger 

 than any figured froai Spitzbergen, and neither the 

 foliage nor the fruit of the northern fossil Ginkgo, it 

 appears, ever at any time approached those of the 

 existing tree in its native habitats. It is now indigenous 

 to the northern provinces of China, and must therefore 

 be capable of withstanding a rigorous climate ; yet the 

 conditions in Western Europe do not appear to favour 

 the ripening of its seed in higher latitudes than the 

 South of France. 



Its distrioution during the Tertiaries is instructive, 

 and Saporta' s explanation, that it existed in the north 

 during the warm Eocene and pre-Eocene times, and 

 descended thence across Europe as the temperature de- 

 creased, on the approach of the Miocene time, is the 

 only one that explains the facts. To suppose with Heer 

 that the same species lived contemporaneously and at 

 the same level in Italy and in Disco is absurd, and would 

 presuppose a uniformity of climate sucli as no natural 

 causes could have produced at so recent a geological 

 period. J. Starkie Gardner 



NOTES 



The Roman Academy of Sciences has awarded half of the • 

 King Humbert Prize, now awarded for the firat time, to the 

 German astronomer, Dr. Wilhelm Tempel, director of the Acetri 

 Observatory at Fljrence, for his observation i on nebula;. 



Death is levying heavy contributions from the students of 

 entomology in France, more especially as regards the oldest and 

 best known. We very recently had occasiDn to notice the 

 decease of Etienne Mulsant, at a ripe age. Now, we regret to 

 have to announce the death of Acliille Guenee of Chateaudun, 

 whose name is probably more known in England than is that of 

 any other French entomologist. He died on the 30th ult. (his 

 c illeague and fellow-worker, Dr. Boishival, died on December 

 30, 1879), in his seventy-second year. Guenee was a lepi- 

 dopterist. His publications are very numerous. The most 

 important of all are the six volumes of the series termed the 

 "Suites a Baffin" on some of the principal families of the 

 Lfpidopkra of the world, which appearei from 185210 1S57. 

 Tliese volumes formed a basis for future students of Lepidoptera, 

 and largely influenced those of them among.st our own countrymen. 

 The town of Chateaudun occupies a nit unimportant position in 

 the history of the Franco-Prussian war. Guene-'s house was 

 occupied by the Prussian troops. He himself took refuge in 

 Geneva, and, true to his predilections, studied the L'pidoptcra in 

 the collection of the museum of that city ; the results of his 

 investigations were published. We believe that when circum- 

 stances permitted his return, his own collections were found to 

 have suffered very little damage at the hands of his unbidden 

 guests. He was an ofticer of the French Academy. Our 

 Entomological Society of London elected him one of its honorary 

 members many years ago ; and his friends amongst Englishmen 

 were not few. 



Iowa Du.x'CAN, a poor Aberdeenshire weaver, has presented to 

 the University of Aberdeen his herbarium of nearly 1200 British 

 plants, gathered by him all over the country from Northunber- 

 land to Banff, while acting as a harvest labourer. The story of 

 Duncan was told in Good IVords for 1S7S, by Mr. William Jolly, 

 and now it would seem that the p3or and intelligent weaver is so 

 reduced in circumstances as to be com.>elled to accept parochial 

 relief. Surely the University of Aberdeen ought to do something 

 for him ; and possibly some of our readers may care to send a 

 trifle to John Duncan, Droughsburn, by Alford, Aberdeenshire. 



