HARDWICKE'S SCIENCE-GOSSIP. 



179 



In chapter XII. is an inquiry as to the nature 

 of the supposed embryo sole found upon a species 

 of shrimp. 



"It is generally believed upon the coasts of 

 England and France, that Soles are produced by 

 means of a certain Species of Shrimp or Prawn, 

 which differs from the ordinary Sole, being of a 

 lighter Colour and much more transparent. I find 

 the same Opinion current among the Fishermen in 

 Portugal, where this kind is known by the name of 

 the Sole-bearing Shrimp." 



Mr. Needham does not, however, believe in the 

 truth of this assertion, although M. Deslandes, in 

 1he Memoirs of the Royal Academy of Sciences, 

 1722, says that he took a considerable quantity of 

 these shrimps and preserved them alive in a quan- 

 tity of sea-water, where, after the space of twelve 

 or thirteen days he found eight or ten little soles. 

 He repeated the experiment several times, always 

 with the same success. He could never succeed in 

 obtaining young soles from the spawn deposited in 

 the vessel in which he had kept some soles a con- 

 siderable time ; from whence he concludes that the 

 spawn of the Sole requires the assistance of the 

 Shrimp to hatch it. The author's figure of the 

 supposed sole embryo represents a maggot-like 

 organism, consisting of nine segments, one of 

 which (representing, probably, the head) is about 

 one-third of the length of the whole form; the 

 remaining eight are equidistant, and apparently 

 armed with a short spine or claw on each side. 

 The author says they are legs, and that the size of 

 the insect is about that of a grain of coarse sand. 



Contemporary with Baker and Needham was 

 George Adams, senior, the author of " Micrographia 

 Illustrata; or, the Knowledge of the Microscope 

 explained, with a Translation of M. Joblot's 

 Observations on the Animalcula found in many 

 Infusions, and an Account of the Fresh-water 

 Polype, translated from the Treatise of Mr. 

 Trembley. 4to, pp. 263, plates 65. London : 



1747." 



Twenty-four years afterwards, the fourth edition 

 of the above-named work was published. This was 

 an 8vo. of 325 pages and 71 plates. 



In 1787, George Adams, junior, produced his 

 Essays on the Microscope, containing a practical 

 description of the most improved microscopes, 

 with a general history of insects. 4to, pp. 720, 

 plates 26. A second^ edition of the Essays, with 

 considerable additions and improvements by F. 

 Kaumacher, appear jl in 179 The considerable 

 additions consisted of four extra pages and six 

 plates. 



Mr. Roper, in his valuable Catalogue of Works 

 on the Microscope, says that "the earliest work 

 I have been able to meet with on microscopical 

 subjects is Petrus Borellus : ' De vero Telescopii 

 Inventore, cum brevi omnium Conspiciliorum 



Historia; accessit etiam Centuria Observationem 

 Microscopicarum.' Small 4to. pp. 188, woodcuts. 

 Hague, 1665—1656." 



But as Borellus dates the invention of the 

 Microscope as early as 1590, it is probable some 

 of the discoveries made with it were published 

 previously to the appearance of Borellus's book. 

 According to the Catalogue just quoted, 115 works 

 on the microscope and microscopic works were 

 published between 1656 and 1799, several of them 

 reaching to third and fourth editions. 



The discoveries of most value were those made 

 by the simple microscope. The observations made 

 by its means were not liable to the errors which 

 the " double " instrument almost always caused the 

 user to fall into. This is very clearly shown in the 

 work done by Leeuwenhoek. 



We append his epitaph, which a correspondent 

 communicated to Notes and Queries (p. 292, vol. iv., 

 series iv.) : — 



"Pise et set. Mem. Antonii A. Leeuwenhoek 

 Reg. Angl. Societ. Membri, qui Naturae penetralia 

 es physices arcana Microscopiis ab ipso inventis et 

 mirabile arte fabricatis, assiduo studio et perscru- 

 tatione delegenda et idiomate Belgico describenda 

 de toto terrarum orbe optime meruit. Nat. Delph. 

 xxiv. Oct. a mvi°xxxij. Ibidemque Denat. xxvj. 

 Augusti a mvij c xxiij. Patri charissimo hoc monu- 

 mentum filia Maria A. Leeuwenhoek moerens P." * 



{To be continued^) 



THE RESTING-SPORES OF THE POTATO- 

 DISEASE FUNGUS. 



By Wokxhington G. Smith, F.L.S. 



IT is with much pleasure that we lay before our 

 readers the following important paper by Mr- 

 W. G. Smith, copied from the Gardeners' Chronicle. 



"The resting-spores found by me in the dis- 

 eased Chiswick potatoes last July have now, after 

 nearly a whole year's rest, germinated and repro- 

 duced the fungus which causes the Potato disease. 

 I propose to publish my observations, with illustra- 

 tions, but before doing so, it may be well to briefly 

 glance at the diverse opinions expressed in different 

 quarters as to the possible nature of the much- 

 discussed bodies referred by me last year to the 

 resting-spores of the Potato fungus. 



" My judges, though numerous, have been the 

 reverse of unanimous, but they have nearly all been 

 friendly and just. Had my critics been unanimous 

 in considering my resting-spores as belonging to 

 some other known fungus distinct from Peronospora 

 infestans, I should have looked on my first observa- 

 tions with great distrust. Strangely enough, how- 



* Leeuwenhoek is buried in the old church at Delft. 



