February 25, 1892J 



NATURE 



399 



School of that town. Bates was at that time an ardent 

 entomologist, while Wallace was chiefly interested in 

 botany ; but the latter at once took up beetle-collecting, 

 and after he left Leicester the following year kept up an 

 entomological correspondence with his friend. Two years 

 later Wallace proposed a joint expedition to Para in 

 order to collect insects and other natural objects, attracted 

 to this locality by the charming account of the country in 

 Mr. W. H. Edwards's " Voyage up the Amazon," a choice 

 confirmed by the late Edward Doubleday, who had just 

 received some new and very beautiful butterflies collected 

 near the city of Para. The two explorers sailed from 

 Liverpool in April 1848, in a barque of 192 tons burthen, 

 one of the very few vessels then trading to Para, and the 

 results of their journey are well known to naturalists. 

 They made joint collections for nearly a year while stay- 

 ing at or near Para, but afterwards found it more con- 

 venient to take separate districts and collect independently. 

 Bates spent eleven years in the country, divided pretty 

 equally between the lower and the upper Amazon, and he 

 amassed a wonderful collection of insects. Returning home 

 in 1859, he devoted himself to the study of his collections, 

 and in 1861 read before the Linnean Society his remark- 

 able and epoch-making paper on the Heliconidae of the 

 Amazon Valley. In this paper, besides making important 

 corrections in the received classification of this group and 

 its allies, he discussed and illustrated in the most careful 

 manner the wonderful facts of " mimicry," and for the 

 first time gave a clear and intelligible explanation of the 

 phenomena, their origin and use, founded on the accepted 

 principles of variation and natural selection. In spite of 

 countless attacks — usually by persons who are more or 

 less ignorant of the facts to be explained — this theory still 

 holds its ground, and notwithstanding the constant ac- 

 cumulation of new facts, and its discussion by new writers, 

 it has never been more clearly or more fully explained 

 than by its original discoverer. 



So early as March i860, Mr. Bates commenced a series 

 of papers for the Entomological Society, under the title 

 of " Contributions to an Insect Fauna of the Amazon 

 Valley." These were at first devoted to the Diurnal 

 Lepidoptera, and in one of them he gave a new classi- 

 fication of the whole group, founded chiefly on the structure 

 of the legs, and leading to the conclusion that the Papi- 

 lionidae formed one of the lowest families, while the 

 Nymphalidae were 'the highest. This classification has 

 been very generally adopted by entomologists, though 

 there are a few dissentients, who hold that the principle 

 adopted to determine the rank or grade of the respective 

 families is an unsound one. Later on he wrote many 

 papers on the various groups of Longicorn beetles ; and 

 finding that his circumstances and the time at his disposal 

 did not allow him to keep up and study two such exten- 

 sive groups as the Coleoptera and Lepidoptera, he parted 

 with his fine collection of South American butterflies to 

 Messrs. Salvin and Godman, and thereafter devoted him- 

 self exclusively to the study of Coleoptera. Later still, he 

 almost confined his attention to the Carabidae, on which 

 important group he became a recognized authority. His 

 largest works in this direction were his contributions 

 to the " Biologia Centrali-Americana" : Vol. I., Part i 

 (Geodephaga) ; Vol. II., Part 2 (Pectinicornia and 

 Lamellicornia) ; Vol. V. (Longicornia). A supplement 

 to the Geodephaga has since been published in the 

 Transactions of the Entomological Society of London 

 for 1890 and 1891 ; and a supplement to the Longicornia 

 was in course of preparation, but not finished at the 

 time of his death. 



In 1864, he was appointed Assistant Secretary to the 

 Royal Geographical Society, an appointment he held till 

 his death. Besides editing the Journal and Proceedings, 

 and carrying on an immense correspondence with travellers 

 and others in every part of the world, he had practically 

 the entire management of the large establishment of the 

 NO. I 165. VOL. 45] 



Society, and the chief burden of the arrangements for the 

 various meetings, as well as those for the Geographical 

 Section of the British Association. There can be little 

 doubt that it was the confinement and constant strain of 

 this work that weakened his constitution and shortened a 

 valuable life. 



When we consider the originality and clearness of ex- 

 position in his first great paper on " Mimicry," the 

 accuracy and fulness of knowledge displayed in his 

 systematic and descriptive work, and the power of obser- 

 vation and felicity of style which characterizes " The 

 Naturalist on the Amazons," we cannot but regret that 

 circumstances should have compelled him to devote so 

 much of his time and strength to the mere drudgery of 

 office work, and be thereby to a great extent debarred 

 from devoting himself to those more congenial pursuits in 

 which he had shown himself so well fitted to excel. 



His high reputation, both as a hard-working entomologist 

 and philosophic naturalist, led to his being twice chosen 

 President of the Entomological Society of London, first 

 in 1869, and again in 1878 ; while he was elected a Fellow 

 of the Royal Society in 1881. His somewhat rugged 

 features, quiet, unassuming manners, and thoughtful 

 utterance, must be familiar to all who have attended the 

 evening meetings of the Royal Geographical Society 

 during the last twenty-seven years. Rarely has any 

 Society had a more efficient 'secretary, who not only 

 carried on its work with accuracy and judgment, but also 

 gained the respect and esteem of all who came in contact 

 with him. He died on Febuary 16, at the age of sixty- 

 seven. A. R. W. 



THOMAS ARCHER HIRST. 



WE regret to have to record the death of Dr. Hirst, 

 the well-known mathematician. He was the 

 youngest of the three sons of Mr. Thomas Hirst, a wool- 

 stapler, and was born at Heckmondwike, in Yorkshire, 

 ' on April 22, 1830. In 1844 he became an articled pupil of 

 Mr. Richard Carter, land agent and surveyor at Halifax ; 

 but afterwards he went to Germany, and studied at several 

 Universities, taking the degree of Doctor of Philosophy 

 at Marburg in 1852. His intercourse with Steiner, at 

 Berlin, gave a strong impulse to his studies, and ulti- 

 mately determined their character. Dr. Hirst on his 

 return to England filled the vacancy at Queenwood 

 College caused by Tyndall's appointment to the Profes- 

 sorship of Natural Philosophy in the Royal Institution. 

 The work at Queenwood occupied most of his time, so 

 that during the three years for which he held the post his 

 only original paper was a note " On the Existence of 

 a Magnetic Medium" (R.S. Proc, vii., 1854). 



Towards the close of 1854 he married, and in conse- 

 quence of his wife's delicate health he passed the winter 

 of 1856-57 in the south of France. During this period 

 he wrote two papers "On Equally Attracting Bodies" 

 {Phil. Mag., xiii., xvi.).^ On the return journey Mrs. 

 Hirst died (1857) in Paris. After this sad event Dr. 

 Hirst spent six weeks with Prof. Tyndall on the iner de 

 glace (cf. " Glaciers of the Alps ") : he then returned to 

 Paris, and attended the lectures of Chasles, Liouville, 

 Lamd, and Bertrand. At this time he translated Poin- 

 sot's famous memoir " On the Percussion of Bodies," and 

 contributed a paper, " Sur le Potentiel d'une Couche in- 

 finiment mince comprise entre deux Paraboloides EUip- 

 tiques" (Liouville,/. de M., ii., 1859).'-' The winter of 

 1857-58 was spent in Rome. Here was written for 

 Tortolini's Annali the memoir " Sur la Courbure d'une 

 S^riede Surfaces et de Lignes" (vol. ii., 1859), an abstract 

 of which was subsequently published in the Quarterly 

 Journal of Mathematics. In these stirring times Dr. 



> Cf. Chasles, " Rapport sur les Progrcsdela Gcometrie," p. 144. 

 - Chasles, " Rapport," p. 303. 



