78 



HARDWICKE' S SCIENCE-GOSSIP. 



desmids (in part) and diatoms, and in his latest 

 publication (" Fortsetzung der Mikrogeologischen 

 Studien," 1875) he adheres to the name Polygastrica, 

 in which he includes the diatoms. The position of 

 the Diatomaceae in the vegetable kingdom is now 

 generally admitted, although there are some few 

 writers who think that they really occupy a neutral 

 position. 



Although many of Ehrenberg's views are now 

 known to be erroneous, and his figures are incorrect, 

 owing to the imperfect objectives he used, and the 

 want of sufficient magnification, his labours will always 

 be of value to the micro-biological student, parti- 

 cularly to those who make the diatoms their study. 

 We therefore hope that this brief account of his first 

 great work (his second is the " Mikrogeologie," 2 

 vols, folio, pp. 493, plates 40, 1854), and the follow- 

 ing resume of his introduction to the Bacillaria will 

 be of interest to the diatomist. 



The Bacillaria. 



The first form belonging to this family was pro- 

 bably discovered by Leeuwenhoek in the year 1 702, 

 and Joblot in 17 16, and which they named Vibrio 

 Bacillus ; it does not, however, appear to be distinct 

 from Synedra ulna. Baker in 1754 detected what 

 was perhaps Naviculafulva and Acineta tuberosa (the 

 latter, I need scarcely remark, is not a diatom, nor 

 at all like one — F. K.). O. F. M tiller observed in 

 1 773 as a distinct member of this family Gomphonema 

 truncatum, which he described under the name of 

 Vorticella pyraria, and confused it with Carchesium. 

 Schrank in 1776 appears to have intended by his Chaos 

 infusoruiu, Naviculafulva. O. F. Midler described 

 in 1779 Achnanthes brevipes as the pubescence of his 

 Conferva hirta, which he had discovered at Pyrmont. 

 In the year 1782 he detected in the water from the 

 Ostsee that wonderful Bacillaria composed of many 

 little staves sliding on each other, which he describes 

 in 1786 as Vibrio paxillifer. 



This form was the first that gave special physiolo- 

 gical interest to this family. 



Professor Hermann of Strassburg had previously 

 to this (1784) published some observations on two 

 Enchelys (JVav. gracilis (?) A r . pJuenicenteron), and a 

 Vibrio (N. librile), all of which belong to this family, 

 but the figures are imperfect. Midler in 1783 de- 

 scribed a Fragilaria and a Gaillonella as plants 

 under the name of Conferva pectinalis and armillaris. 

 In his posthumous work (" Animalcula Infusoria 

 Fluviatilia et Marina quae detexit, systematica de- 

 scripsit et ad vivum delineare curavit," 4to, 50 plates, 

 Haunioe, 1786) he places among the Protozoa his V. 

 paxillifer, V. bipunctatus (Synedra ulna?) V. tri- 

 punctatus (N. gracilis) as synonyms of Professor 

 Hermann's Enchelys ; he also figures an Acineta as 

 Vorticella tuberosa. 



Colombo ( " Osservaz. microsc. inGiornale perservir 



alia stor. raggion della medicina," t. iv. Venez. 1787, 

 p. 1, afterwards translated at Leipzig, 1793, t. i. f. 4) 

 described in 1787 the before-named G. truncatum as 

 a plant-like animal. Gmelin (1788) considered 

 Midler's jointed Bacillaria a distinct genus (Bacil- 

 laria paradoxa), and placed it in the animal kingdom. 

 Vahl, in the "Flora Danica," and the editor of the 

 " English Botany," describes many of the Bacillaria 

 as plants, but Schrank (1797) placed a number of 

 these forms with the Protozoa ; he also described two 

 Navicula under the names of Vibrio turrifer and 

 fuscus, and Cocconema as Kolpoda luna. 



Kammacher also figures (1798, in Adams's " Micro- 

 graphia") a Navicula (gracilis) as an animal. Since 

 the year 1797, a number of important innovations 

 have been made in this study, by Girod Chantrans, 

 who supported them by his laborious but uncritical 

 observations, and affirmed that many of the moving 

 Algae produced animals, that these animals again 

 became torpid motionless Algse, and that Conferva 

 were Polypstems (Polypenstocke). That the Navicula; 

 originated from Oscillatoria, and that their ova 

 produced the Byssusflos aqinv, &c. This was detailed 

 very fully by him in 1802. Since then only Ingen- 

 housz has published similar information, asserting 

 that the moving or animal-like condition of these 

 little bodies became transformed into motionless 

 plant-like organisms, and with more or less decision 

 maintained that in these forms, not only was their 

 animal or plant-like nature very undecided, but even 

 that they belonged to the mineral kingdom. Roth, 

 Decandolle, Dillwyn, Draparnaud, Grateloup, 

 Hornemann, Thore Agardh, and Hooker designated 

 the forms of this family as plants. Decandolle, in 

 1805, gave the name diatoma (which Loureiro had 

 previously given to a phanerogamic plant) to two 

 generically different forms, Striatella and a Fragil- 

 aria. Achairus in 1805 designated the radiating 

 threads of ova belonging to some aquatic insect, 

 Echinella radiosa, considering it to be an Alga. 



In 1802 Agardh published the new generic name, 

 Gloionema. In the important researches of Nitzsch, 

 published in 1816-1 7, he placed the Diatomece, pris- 

 matic Vibrios, and the related Conferva of the 

 botanist (and which had previously constituted the 

 older genus Bacillaria) in the animal kingdom. He 

 was of opinion that some forms were wholly vege- 

 table and others wholly animal. 



In 1819 Lyngbye constructed the genera Bangia 

 and Fragilaria, the first partly, and the second en- 

 tirely belonging to the Bacillaria, and extended the 

 limits of the genus Echinella. Link (1820) published 

 two genera of plants Hydralinum and Lysigonium, 

 which probably correspond witli the genera Schizo- 

 nema and Gaillonella, but they are very imperfectly 

 described. In 1S22 Bonnemaison introduced two new 

 genera of plants, Vaginaria and Spermogonia, and 

 which are, perhaps, also species of Schizonema. 



About this time Bory de St. Vincent added the new 



