HARDWICK&S SCIENCE-GOSSIP. 



189 



the five-banded kind. So far as I have been able 

 to observe, it is the lower bands which are more rarely 

 absent and generally the upper ones which are so, 

 and my attention has recently been considerably 

 drawn to this in the case of H. kortensis. Near 

 Oswestry the type form is common, but of the un- 

 handed I did not take one specimen among many 

 hundreds observed. The band variation in these 

 shells was entirely confined to the upper bands, 

 which were sometimes thinned out, sometimes alto- 

 gether absent. In conclusion, I may say that I have 

 never taken a specimen of either H. ncmoralis or 

 H. hortensis possessing the upper and lacking the 

 lower banding. — Baker Hudson. 



Rana macrocnemia. — In the lately issued num- 

 ber of the " Proceedings of the Zoological Society of 

 London " is a figure of a new species of frog from 

 Asia Minor. Mr. G. A. Boulenger, F.Z.S., proposes 

 to give the name of Rana macrocnemia to this frog, 

 whose nearest ally is R. temporaria, and from which 

 it differs in the longer hind limbs and in a few other 

 respects. 



Abdominal Legs of Caterpillar. — The 

 "American Naturalist " for July contains a note by 

 A. S. Packard on the caterpillar of Lagoa crispata, 

 Pack., which possesses the unusual number of seven 

 pairs of abdominal legs, and which was first described 

 by him in 1S64. It is believed to be the only cater- 

 pillar which has more than the normal five pairs of 

 abdominal legs. Two pairs out of these seven pairs 

 are rudimentary, and as the embryology of Sphinx 

 has shown that it has ten pairs of abdominal legs, of 

 which five pairs disappear before hatching, it is 

 supposed that these rudimentary ones in Lagoa may 

 be the survivals of ten pairs of embryonic legs. 



BOTANY. 



Close-Fertilisation of Orchids. — Professor 

 Henslow contributes an article on this subject to the 

 " Gardeners' Chronicle," in which he refers to a paper 

 read at the Linnean Society last December, on 

 " Contrivances for Insuring Self-fertilisation in some 

 Tropical Orchids," by Mr. H. O. Forbes. Mr. 

 Forbes called attention to the general fact that, in 

 Portugal and the Tropics, Orchids, especially adapted 

 for insect agency, are to an enormous extent utterly 

 barren (not two per cent, of the flowers in one case 

 being fertilised), and described several species which 

 exhibit remarkable adaptations for close-fertilisation, 

 thereby more or less preventing cross-fertilisation, 

 and which yet produce abundant seed. Mr. Henslow 

 takes the opportunity of questioning the necessity of 

 cross-fertilisation. He thinks there is no a priori 

 ground for assuming that Nature abhors self-fertilisa- 

 tion, and alludes to the large number of cleistogamous 



flowers, including one in orchids, described by Mr. 

 Forbes. He holds that there is no experimental 

 verification of the theory that close-fertilisation brings 

 about physical weakness, and leads to the extinction 

 of the plant. He refers to his paper on "Self- 

 Fertilisation," in Trans. Linn. Soc. vol. i. p. 17, 

 1879, as showing that, — keeping in view the only two 

 ends of plant life which he thinks can be recognised, 

 viz. self-preservation and the production of numerous 

 healthy offspring, — self-fertilising plants are incom- 

 parably the better off. Species adapted for cross- 

 fertilisation are generally larger plants than allied 

 species adapted for self-fertilisation, and have finer 

 foliage and more handsome flowers, being thus of 

 more value to the horticulturist. Mr. Forbes de- 

 scribed Phaius Blumei, which was self-fertilising. 

 In Spathoglotiis plicata and another case the flower 

 was self-fertilised before it opened, an approxima- 

 tion to cleistogamy — Plocoglottis (?) being absolutely 

 cleistogamous. From these and other cases, both of 

 orchids and other plants, Mr. Henslow says that all 

 degrees of transition may be found between flowers, 

 apparently well adapted for inter-crossing, yet also 

 adapted for self-fertilisation, and cleistogamous 

 flowers, many exhibiting adaptations for both pur- 

 poses. Wherefore he traverses Mr. Darwin's con- 

 clusion with respect to the Bee Ophrys, when Mr. 

 Darwin says that the survival in it of the apparatus 

 for cross-fertilisation, though the flower is mainly 

 self-fertilised, points to the fact of cross-fertilisation 

 at long intervals. Apropos of this subject, some very 

 interesting remarks by Mr. A. R. Wallace may be 

 found in a review by him, in " Nature," of a book of 

 travels in the Fastern Archipekgo by Mr. H. O. 

 Forbes. Mr. Forbes remarks, that the cross-fertilisa- 

 tion of orchids is by no means so universal as has 

 been supposed. (This is probably the sense, though 

 concealed by an apparent misprint.) He mentions a 

 plant related to Chrysoglossum in which, though the 

 labellum is beautifully marked with lines of purple, 

 carmine, and orange, and the column also, the flower 

 fertilises itself without ever opening at all. 



GEOLOGY, &c. 



Geology of the Highlands. — In the first part 

 of his paper on the Age of the Malvern Hills (p. 126), 

 Mr. J. Walter Gregory seems to attribute the changed 

 view of the nature of the rocks of the Highlands of 

 Scotland to the investigations of Dr. Geikie. Of this 

 question a somewhat detailed account may be found 

 in the presidential address of Professor T. G. Bonney 

 to the Geological Society last February. Having 

 mentioned the important event of the abandonment 

 by the director general and other Survey officers of 

 the Murchisonian hypothesis, Professor Bonney shows 

 that, before the end of the year 1S83, in the summer of 



