532 



NATURE 



[Oct. 6, 1 88 1 



Cretaceous series. I need not refer to the Miistricht beds, except 

 to notice that a mixture of Tertiary and Cretaceous types of 

 moUusca is also apparent in them. One circumstance, however, 

 lessens the value of the evidence presented by the mollu-ca and 

 the flora ; we are so little acquainted with either the Gastropods, 

 the Dimyaria, or the plants of the White Chalk age, that it is 

 possible these may have inclined more to Tertiary types than 

 those of the Grey Chalk would lead us to suspect. 



I believe that in the American Cretaceous molluscous faunas 

 there is precisely the same mingling of types described above, 

 and if so, they should surely be bracketed together, rathtr 

 than with our Neocomian Gault, or even Grey Chalk, which 

 present no such mixture and contain few Tertiary types, ex- 

 cept in unimportant groups, as Dentalium. Further, we mnst 

 not overlook the oft-repeated negative arguments that we have 

 no dicotyledonous plants of these ages in Europe, and tliat 

 Baciditcs, &c., may have survived longer in America than in 

 Europe. Ttie whole series in America forms, so far as I gather, a 

 natural sequence, the age of one part of which, the Laramie, 

 can be fixed as Middle Eocene, and I think, before correlating 

 the remainder with the older Cretaceous beds of Europe, with 

 which neither their fauna nor flora agrees, the position occupied 

 in the American series by the older Eocene, and the transition beds 

 which I have enumerated, should be as far as possible ascer- 

 tained. The matter is thus still, and must remain for the 

 present, in an unsatisfactory state ; but the importance of re- 

 moving all doubt as to the relative position of those American 

 beds which have yielded such magnificent palreontological data, 

 and of the more typical British strata, is so great that 1 hope 

 Prof. Ne.vbeny will not let the subject drop. 



J. S. Gardner 



Gradations between Hermaphroditism and Gynodicecism 

 - Abortion of the stamens in some portion of the flowers 

 occurs in different species of the genus Dianthus. D. supirhu^ 

 has been shown to be gynodiceciuus in my work on " Alpen- 

 blumen " (p. 202, Fig. 79). D. ddtoides, the only species 

 grov\ ing near Lippstadt, has lately been examined by myself, and 

 has been found under certain circumstances to become gyno- 

 monoecious and gynodicecious. Of D. Ccirtkusiaiwrum among 

 167 flowerinij stalks sent me from Thuringia by my brother, 

 Wilhelm Miiller, there were two producing female flowers with 

 greatly aborted stamens. D. dcltoidcs near Lippstadt offers 

 interesting gradations from hermaphroditism to gynodicecism. 

 On the border of a meadow of some hundred stems examined by 

 myself, all flowers, without exception, proved proterandrous, with 

 normal development of anthers and stigmas. In the grass-grown 

 slope of a sandy hill ("die Weinberge") likewise all stems pro- 

 duce proterandrous flowers, but on many stems the stamens, 

 although emerging above the petals before the development of 

 the styles and stigmas, bear diminished whitish anthers not 

 opening at all, and containing only some shrivelled pollen grains. 

 Lastly, in a barren sabulous locality (" Schiitzenplatz ") many of 

 the stems produce female flowers, with stamens aborted in the 

 same degree as shown in Z>.«(/'cr(5;« (" Alpenblumen," Fig. 79 D), 

 and not unfrequently such female flowers and proterandrous 

 hermaphrodite ones are found on the same stem. 



Lippstadt Hermann Mijller 



Red Stars 



Dr. Doberck, who has paid particular attention to colour in 

 his observations of Doubles, has kindly sent me the following 

 list of red stars found by him in 1S80. The first column gives 

 the number, and the second and third the positions (for 1855) in 

 the B.D. :— 



Dr. Doberck remarks that the two stars on both sides of tj Dra- 

 conis are pale red ; and in Coma Bey, and south of it are several 

 ruddy stars. J. Birmingham 



Millbrook, Tuam, September iS 



Bombay Rainfall and Nile Floods 



In looking over data of the rainfall at Bombay and comparing 

 them with the ebb and flow of the Nile for the corresponding 

 years from 1849 to iSSo inclusive, I was so struck with the 

 similarity, almost identity, of magnitudes, that I have been led 

 to copy them out, and perhaps you may consider them worthy of 

 publication in your most valuable journal. Within a trifling 

 fraction the whole of the annual rainfall at Bombay happens in 

 the months of June, July, August, and September. Very rarely 

 a little falls in May, perhaps a little more frequently, .some in 

 October, but these small quantities but slightly augment the sum 

 total. They are included in the four months' totals in the follow 

 ing table : — 



The floods of the Nile are mainly caused by the heavy rains 

 which descend up m the high tablelands of Abyssinia, a range of 

 mountains on the opposite side of the Indian Ocean to that of 

 the Ghauts, but parallel to them and under the same latitudes. 

 The inference to be drawn is obvious. The gi-eat south-west 

 monsoon which sweeps over the Indian Ocean in the summer 

 months produces a Uke effect in both cases, inducing fertility and 

 plenty, alike on the plains of the Concan of India and the Delta 

 of Egypt. It may be mentioned that the lowest ebb of the Nile 

 always happens in June, and the highest flood about the end of 

 September and the beginning of October. I have included in 

 the table a column showing the variations of the mean baro- 

 metrical pressure, and a column giving Wolf's observation of 

 sun-spots, taken from Nature, vol. xxi. pp. 477-82. 



Morgan Brierley 

 Port Said, September 8 



