59- 



NATURE 



{Oct. 20, 1887 



the'author mentioned the discovery of a very peculiar genus Nao- 

 saurus (Cope). Then he explained some unpublished plates of 

 Ctenodus, Orthacanthus, Ctenacanthus, and a new Ganoid Fish 

 (Trissolepis), with three kinds of scales. Then he proved 

 Acanthodes to be very near to the Selachians, and drew attention 

 to the gigantic fish (Amblypterus), 113 cm. long, exhibited in the 

 galleries. 



Section D — Biology. 



Proposed Contributions to the Theory of Variation, by Patrick 

 Geddes. — The author argued that the variations which furnish the 

 distinguishing characters of orders, genera, or species alike are 

 seen to be not merely " spontaneous " or "indefinite,"but parallel, 

 or rather convergent ; i.e. directed through the checking of vegeta- 

 tion by reproduction along a definite groove of progressive change. 

 Passing from the study of the flower to the larger question of the 

 classification of plants, an antagonism between nutrition and repro- 

 duction is seen to be general and constitutional, affording a con- 

 stant factor in variability. In every natural alliance of flowering- 

 plants, be it species or genus, order or class, we can distinguish 

 the appearance of a predominantly floral, and of a predominantly 

 leafy, or weedy, type ; i.e. of a reproductive and vegetative one. 

 What we figuratively call higher or lower species are thus 

 essentially the leaders or the laggards along one or other of these 

 two main lines of evolution — the representatives on one side or 

 other of this or that stage in the rhythm between vegetative 

 and reproductive changes which we know as the essential functions 

 of organic life. 



On the Structure of Haplodiscus piger, by W. F. R. Weldon. — 

 This remarkable organism consists of an outer cuticle within 

 which is a protoplasmic layer with interspersed nuclei ; this 

 protoplasmic layer is continuous with a network which ramifies 

 through the body ; in the middle of the body and towards the 

 under surface the network is condensed into a solid ma<s which 

 sends out pseudopodia-like processes and is evidently an organ 

 of nutrition ; the interstices of the network are occupied by the 

 reproductive organs ; there is a vesicula seminalis communi- 

 cating with the exterior by an ejaculatory duct. The author 

 compared this organism to a Foraminifer, such as Haiiphysema, 

 which had developed sexual organs. 



On the Degeneration of the Olfactory Organ of certain Fishes> 

 by Prof. Wiedersheim. — The author described a remarkable 

 series of intermediate forms between a species of Tetrodon in 

 which the olfactory organ was represented by a bifid tentacular 

 outgrowth on each side, and another form in which these organs 

 had degenerated into a simple flat plate. 



On the Torpid State of Protopterus, by Prof. Wiedersheim. — 

 In this paper the structure of the "cocoon"' was described, and 

 the author announced the startling discovery of a peculiar 

 respiratoiy organ in the tail of the fish ; the relations of this 

 organ to the lungs during the torpid condition is not known. 



The Larynx and Stomach of Cetacean Embryos, by Prof. 

 D'Arcy Thompson. — The author pointed out that the divisions of 

 the stomach in the Cetacea, do not really correspond to those 

 of the Ruminants, with which they have been erroneously com- 

 pared. 



The Blood Corpuscles of the Cyclostomata, by Prof. D'Arcy 

 Thompson. — The red blood corpuscles oi Myxine are oval, as are 

 also those of the larval lamprey. The adult lamprey has round 

 corpuscles. 



On the Luminous, Larviform Ftj?iales of the Phengodini, by 

 Prof. C. V. Riley. — Certain interesting phosphorescent Coleo- 

 pterous larvse, reaching from 2^ to 3 inches in length, have been 

 well known to occur in America since 1862. Prof. Riley gave 

 a minute description of these larvje, calling attention to certain 

 structural features of the head, and to other points. 



The great interest attaching to these larvae is not so much in 

 their luminosity as in the fact that a portion of them are now 

 known to be true and perfect females of Phengodini, which have 

 until recently been represented in Coleopterological collections 

 in the male sex only. 



Prof. Riley has critically examined in all some thirty different 

 sets of specimens. These all belong to Phengodes and Zarhipis, 

 with the exception perhaps of one, which may be Spathizus. The 

 differences between the larvse proper and the adult female are 

 so slight that it was difficult to separate them without some 

 absolute index. Prof. Riley had obtained undoubted females, 



coupled with their males, of Phengodes laticollis and Zarhipis 

 riversii, and in both genera there were absolutely no other 

 structural differences than the somewhat shorter mandibles and 

 tarsal claws in the adult. In reference to life-history, the food of 

 Zarhipis is known to be Myriapods. The eggs in both genera 

 are spherical, translucent, and laid in masses in the ground, the 

 newly-hatched larvre in both are structurally identical with the 

 parent ; and the female larva goes through a pseudo-pupal state 

 prior to the final moult. Nothing is yet kn&wn of the male larva 

 and pupa, and the author only conjectures that certain darker, 

 more slender larvae, structurally identical, belong to this sex. 

 The author discussed the bearing of the facts on the theory of 

 evolution. In these larviform females we get a glimpse, so to- 

 speak, into the remote past, from which has been handed down 

 to us, with but little alteration, an archetypal form which pre- 

 vailed before complete metamorphosis had originated ; while on 

 the other hand her male companion, during the same period, 

 had developed wing-power and the most elaborate and com plex 

 sensorial organs, the eyes and antennae in these beetles being 

 among the most complex of their order. Whatever we believe 

 of the origin of the female Phengodes, one thing is self-evident %. 

 viz. that there is direct relation between the phosphorescence 

 and the remarkable differentiation of the sexes, and, further, 

 that such relationship is explicable and full of meaning on 

 evolutionary grounds. 



A discussion upon The Present Aspect of the Cell Question was 

 opened by Prof. Schafer. After a brief historical resume of the 

 different conceptions of the cell, the speaker brought forward 

 facts in support of his view that the essential part of the cell is 

 not the reticular substance, but the interstitial substance. It 

 was pointed out in the first place that the various materials pro- 

 duced in the cell by the activity of its protoplasm, e.g. fat, 

 appeared in the interstitial substance ; and that, in the second 

 place, the Amoeba presented no reticular substance whatever. 

 The structure of the white blood-corpuscle was also quoted as 

 an additional argument. These corpuscles have a reticulum like 

 that of other cells, but the pseudopodia are prolongations of the 

 interstitial matter ; hence the activity of the cell for movement 

 is lodged in this substance, and not in the reticulum. 



Prof. Weismaun contributed to the discussion an account of 

 his views upon the nature and meaning of polar bodies, announc- 

 ing at the same time the discovery of a single polar body in the 

 parthenogenetic eggs of certain animals. 



Prof. Lankester drew attention to a statement made by the 

 President of the Association in his opening address. Sir H. 

 Roscoe had stated that protoplasm was not a chemical com- 

 pound, but a structure built up of compounds. This statement 

 was indorsed as in harmony with the views of at any rate many 

 biologists. The term protoplasm was originally applied by von 

 Mohl to the whole of the slimy matter within the vegetable cell- 

 wall. But nowadays biologists were more and more limiting 

 the term protoplasm, and applying the term true protoplasm to 

 the chemical substance of highest elaboration, which is the 

 important living part of von Mohl's "protoplasm." Prof. Lan- 

 Iv ester suggested that the term. " plasmogen " should be used 

 for this substance. With regard to the structure of protoplasm, 

 it was considered to be vesicular, the reticulum or walls of the 

 vesicules being that part of the protoplasm in which the plasmo- 

 gen resides which is not contained in the vesicular spaces. The 

 idioplasm and germ-plasm of Prof. Weismann were probably 

 varieties of plasmogen. 



The discussion was continued by Profs. Krause, Carnoy, 

 Marshall Ward, and Hartog, Mr. Gardiner, and Mr. Sedgwick. 



Prof. Riley read a paper upon Icerya purchasi, an Lnsect 

 injurious to Fruit- Trees. — It was stated that this species is the 

 most polyphagous of Coccids, living on a great variety of fruit- 

 trees. As it is capable of moving about at all stages of develop- 

 ment after leaving the egg, and can survive for a long period 

 without food, it is one of the most injurious of parasites. It H^i 

 believed to have originated in Australia and to have been intr<^BI 

 duced into other parts of the world upon living plants. It ^Bl 

 very hard to destroy the eggs by any insecticides because of the 

 fluted waxy ovisac. In California these difficulties have, how- 

 ever, been largely overcome by the use of kerosene emulsions 

 and of resin soaps, as well as by inclosing the tree in a portable 

 tent, which is then filled with certain gases. 



The Hessian Fly, by Prof. Fream. — The Hessian fly was disco 

 veredin Britain in barley-fields near Hertford in July 1886, previoa 

 to which date there is no record of its occurrence in this countryl 



