194 



NA TURE 



\J tine 28, 1883 



Of Mollusks and Crustaceans, M. Gaudry says what 

 he has already said of Brachiopods and other animals. 

 As Dr. Woodward remarks, although Trilobites are 

 always easily distinguishable from other Crustaceans 

 (extinct, of course), one wonders at the astonishing 

 variety afforded by this group of animals. 



Let us pass over the Mollusks to see what M. Gaudry 

 says of fishes and other Vertebrates. 



Fishes begin in the Upper Silurian strata ; they are 

 abundant enough in the Ludlow beds (Pteraspis), and in 

 the Downton grit (bone-bed — Pteraspis, Thelodus, Plec- 

 trodus, and Ctenacanthus). The fishes of the first ages 

 of our globe were very singular animals ; for instance, 

 Didymaspis grindrodi wore on the back a scutum very 

 much like that of a queer little Crustacean — at present 

 very abundant in some places around Paris— named Apu s 

 productus. Pterichthys wore a yet stranger scutum which 

 has been ascribed to insects, to Crustaceans, and to 

 turtles before one could understand its meaning ; it was 

 incased in a bony helmet, and its fore-fins were also 

 incased in a similar envelope, somewhat like the limbs 

 of a crayfish or a lobster. Those primary fishes were 

 sometimes devoid of a vertebral column, and nothing 

 similar to these animals can be found among the living 

 species. It must be therefore conceded that some links 

 are missing, or that they have not existed. 



As to Reptiles, they begin after fishes, in the Carbonife- 

 rous and Permian strata, at the same time that Batrachia 

 appear. The first of these, Protriton petrolei, has been 

 discovered by M. Gaudry in the Permian strata of Autun, 

 in France. Pleuronoura pellatii, Branchiosaurus, Apa- 

 teon, and many others resemble somewhat the Protriton, 

 and M. Gaudry remarks that these little animals are 

 generally abundant in the same strata where Labyrintho- 

 Honts and similar animals are to be found. It may be 

 that some ot them are young Labyrinthodonts. Among 

 ReptilU M. Gaudry seems inclined to consider Archego- 

 saurus and Actinodon as the primitive type, They had 

 no real vertebral column, the brain was imperfectly deve- 

 loped, and the limbs were rather imperfect. It is easy to 

 perceive, by careful study of other Reptilia, that they 

 differ from these only very slightly in some cases. 



M. Gaudry comes to the following general con- 

 clusions : — 



There are certainly links between the Silurian, De- 

 vonian, Carboniferous, and Permian species, and links 

 exist between these and the actually living species of the 

 same groups. Primary Foraminifera, for instance, are 

 very similar to the actual species of our seas and oceans. 

 This is true also of Brachiopods, Polyps, Mollusks, and 

 Trilobites, but less so of Echinodermata. Brachiopods 

 perhaps llustrate this general theory best, since they are, 

 of all animal groups, the only one that has lasted from 

 the beginning of animal life (Lower Silurian) to the 

 present day. 



As d'Omalius d'Halloy says, "It is scarcely credible 

 that the Almighty Being whom I consider as the Author 

 of Nature has, at different times, killed all living animals, 

 to give himself the pleasure of creating new animals, 

 which, very similar to the preceding ones, present suc- 

 cessive differences, and display a marked tendency to 

 blend with the actually living forms." 



Henry de Varigny 



COLIN CLOUT'S CALENDAR 



Colin Clout's Calendar; The Record 0/ a Summer, April- 

 October. By Grant Allen. (London : Chatto and 

 Windus, 1883.) 



OF all the writers in this country who seek to render 

 the facts and the theories of modern science attrac- 

 tive to the general public, Mr. Grant Allen is in our opinion 

 among the most successful. We know that he does not 

 profess to be in any serious manner an original investi- 

 gator of these facts, and we are far from being always 

 ready to accept his theories ; but in most of his writings 

 we meet with a characteristic ingenuity of thought, and 

 perhaps a still more characteristic grace of style, which 

 together render his essays the most entertaining in the 

 kind of literature to which they belong. 



It has recently been said in these columns, with express 

 reference to Mr. Allen, that this kind of literature does 

 more harm than good to the cause of science and to the 

 advancement of the theory of evolution. But here, we 

 think, the most that can be fairly said is that his zeal 

 may sometimes be in danger of outrunning his discretion, 

 so inducing him to trespass upon the domain of scientific 

 questions which a more technical biologist would feel 

 to be precarious ground. We should remember, how- 

 ever, that the function of a popular writer is to make 

 his material attractive to the general reader, and if 

 he succeeds in doing this for science, we think that he 

 deserves to be encouraged by scientific men, even if they 

 find that in running somewhat too fast over the grounds 

 of theory he occasionally trips over matters of fact. Now, 

 as we have said, Mr. Allen, considered as a literary man, 

 is certainly a man of unusual ability, and he devotes his 

 ability to diffusing an interest in biology among readers 

 of periodical literature, who certainly could not be reached 

 by any less attractive means. Moreover, he is a man of 

 originality, both as regards thinking and observing, and 

 if he were to devote less time to spreading out the sweets 

 of science for popular consumption, there can be little 

 doubt that he might do good work in collecting them. 



But, be this as it may, we think that there should be 

 no difference of opinion touching the service which Mr. 

 Allen has rendered in his own province, even if we do 

 not all go so far as to say with Mr. Wallace that he 

 " certainly stands at the head of living writers as a 

 popular exponent of the evolution theory." The book 

 which we have now to notice is restricted to this province, 

 and in its main features resembles those previous 

 volumes which from time to time have been favourably 

 reviewed in these pages. It consists of thirty-nine short 

 papers republished from the St. James's Gazette, the 

 greater number of which are devoted to botanical sub- 

 jects. As the title of the collection suggests, these papers 

 embody a number of observations and reflections on the 

 natural history of plants and animals commonly met with 

 in English country life ; and as the essays are written in 

 the least technical and most graphic language, they might 

 be read with profit by all who take any intelligent interest 

 in these things. 



We may now give a few quotations, which will serve to 

 show the general nature of the book : — 



" But what is most interesting of all about the butter- 

 wort is the fact that it is peculiarly adapted for attracting 



