HARDWICKE'S SCIENCE -GO SSIP. 



A. ojjJiiogramma — one taken in Ireland, where it 

 is exceedingly rare. 



0. lunaris—s. specimen of this insect was taken 

 near Lewes. 



The Pyrales furnish us with one very rare species, 

 A. nemoralis, which has turned up in two or three 

 localities ; viz., at Willesden, Lewes, and in Surrey. 



"Sugaring" has been condemned as an utter 

 failure during the season of 1873, and yet almost all 

 the rare Noctuce mentioned above were taken at 

 "sugar." 



The uncertain appearance of such species as 

 C. edusa and hyale, and of C. cardui, &c., lias 

 been repeatedly noticed, but the subjec" of the 

 occurrence of rarities when common insects are 

 scarce, is one which, in spite of the attention paid 

 to it, has not yet met with a satisfactory explana- 

 tion. M. H. 



HISTORY OE THE DIATOMACE^. 



T)ROEESSOR H. L. SMITH, in the August 

 -*- (1873) part of the Lens, commences a transla- 

 tion of Kiitzing's " Historical Preface " {Ge- 

 schicJdliche Einleltung) to his " Bacillarien " ; and as 

 this preface is of considerable interest to the 

 student of the Diatomacese, we propose to give a 

 short resume of Professor Smith's translation. The 

 translator remarks in a note, that Ihe introduction 

 of Kiitzing's " Bacillarise " {Bacillarien) presents 

 so many points of interest for the student, and is 

 so valuable as an historical summary, that I pro- 

 pose, in the intervals between the appearance of 

 the different parts of my own synopsis, to give a 

 somewhat free, though accurate, translation of it : — 

 "Already, for four thousand years [JaJirtausend , 

 lit. 'thousands of years.'— E. K.l has the mind of 

 man searched the wonder works {Wunderwerken) of 

 creation, yet (still) a vast field remained unexplored, 

 closely connected with the numerous forms of that 

 endless nature which the unaided eye had recog- 

 nized, and the higher probing mind had arranged, 

 when in the commencement of the 17th century, a 

 compound microscope was invented by Zacharias 

 Janson and his son, in Middelburg; and with that 

 man ventured upon the unknown, and till then 

 invisible, field of smallest organisms, the discovery 

 of which opened an entirely new world in minia- 

 ture. 



Althouzh it is uncertain what particular forms of 

 the Diatom group the first observers found and 

 endeavoured to represent by description and pic- 

 ture, yet it may be taken for granted, with great 

 certainty, that they must have met with isolated 

 specimens, since they are so widely distributed. 

 Eor the first discovery of forms which we are able 

 to identify with any certainty we have to thank 

 0. F. Miiller, who, in 1773, described and figured 



' a Gomphonema, under the name of Vorticella 

 i pyraria, and a Fragilaria as Conferva pectinalis, 

 i and a Melosira as C. armillaris. A much greater 

 sensation was produced by the discovery of the staff 

 animalcules {Vibrio paxlllifer) by Miiller, and which 

 the discoverer did not know where to classify, but 

 later embodied in the genus Vibrio. 



Gmelin, in the 13th edit, of Linue's " Systema 

 Naturse," corrected this error, and founded a special 

 genus upon this form, and to which he gave the 

 name Bacillaria, and from this the whole group 

 received the name Bacillarioe, or staff animalcules. 



The lower Algi3e had, at the end of the last cen- 

 tury, very zealous friends {sehr eifrige Freimde) in 

 Germany, in Mertens Trentpohl, Both, Weber, 

 and Mohr ; in England, Dillwyn ; and in France in 

 Girod-Chantrans and Draparuaud ; and several 

 forms now distributed among the genera Fragilaria' 

 Melosira, Diatoma, Tabellaria, and Schizonema, 

 were described by these naturalists as Confervce. 



In the beginning of the present century some 

 good figures of Conferva stipitata {^=Achnanthes 

 longipes) ; C. obliquata { = Isthmia enervis) ; C. 

 Biddulphia {=Biddulphia yiilchella), were given. 



Although De Candolle, so far as is known, made 

 no special study of these organisms, he was the 

 first to separate the form previously known as 

 Conferva flocculosa, as a special genus, which he called 

 Diatoma. Agardh adopted this genus in his 

 " Synopsis Algarura," 1817, but combined with 

 it other species — D.Swartzii, D. pectinalis, D.fiscio- 

 latum, which are now distributed among as many 

 different genera. 



We are indebted to Nitzsch for the most im. 

 portant investigations made by him in the same 

 year. He furnished in his little work, long since 

 out of print, " Contributions to the Knowledge of 

 Infusoria, or a Natural History of the Zerkarise 

 and the Bacillarise," with six coloured copperplates, 

 the first really good pictorial representations. He 

 also first -recognized the prismatic shape of these 

 forms; he correctly observed and explained the 

 separation into zig-zag chains and the production 

 of ribbon-like forms from an imperfect separation 

 (incomplete self-division). In 1819 appeared 

 Lyngbye's Tentamen Bydrophjiologi(P Danicce ; this 

 work contained more Bacillarian forms than any 

 previous publication. Twenty-five different forms 

 were distributed among the genera Diatoma, Fragi- 

 laria, and Echinella. The name of this last genus 

 had been previously given by Acharius, and incor- 

 porated for several years in the systematic hand- 

 books, and had even been given by me in my 

 "Decades of Fresh-water Alga;," to a form which, 

 in the following year (1835), was recognized as 

 insect eggs. 



In 1820, Link described two new genera, Lisi- 

 gotiiuni (not Lisogorium) = Melosira and Hydrolinum 

 ^=ScMzoncma. 



