HARDWICKE'S SCIENCE-GOSSIP. 



79 



genera Achnanthes, Nematoplata (Fragilaria) and 

 Styllaria (Cocconema) to his family of Arthrodiees, 

 which he intended as a connecting link between 

 plants and animals. He also added the genus Navicula 

 to the family Bacillarees, which he placed with the 

 Infusoria, and for which he intended his family 

 Psychodees, although he does not mention it in his 

 " Review of the Infusoria." 



Nees v. Esenbeck in the year 1823 separated the 

 Oscillatoria and some other forms, and constituted a 

 middle class between the Fungi and Algae, under the 

 name of Hydronemata. Schrank again opposed the 

 theory of the Bacillaria being animals, and distributed 

 Midler's genus Vibrio among Bacillaria, Oscillaria and 

 Vibrio. Gaillon of Dieppe in 1823, apparently 

 misled by Girod Chantrans, through his mistaken 

 idea of the breaking up of Marine Algae into Navi- 

 culae, and the union of Naviculae ( Vibrio bipiaic- 

 tatus) through mere juxtaposition with Algae {Giro- 

 della {Conferva) eomoides), created a family of 

 Nemazoaires as Conferva, but which were really 

 Monads or Naviculae collected together. Bory de St. 

 Vincent created in 1823 his genus Gaillonella, which 

 he placed in the family of Conferva. 



Agardh, in 1S24, formed out of the Bacillaria an 

 order of Algae, which he called Diatomeae, and 

 placed the genera Frustulia, Meridion, Meloscira (Gail- 

 lonella), Schizonema (Girodella), Desmidium and 

 Gomphonema in it. He also placed in the order 

 Nostochinae the two genera Echinella and Gloio- 

 nema, both of which had previously belonged to the 

 Diatomeae. 



Link, in 1824, approved of this arrangement, but 

 placing the two last genera in the Diatomeen, 

 and continued D. Leo's (confirmed by Girod 

 Chantrans) observations, and considered the Oscil- 

 latoria as mother forms of Naviculae. Treverarius, 

 Steudel, Fries, and Sprendel, speak of the Bacillaria 

 as plant-like organisms. Fries brought forward the 

 crystalline, or mineral theory. Blainville (1825) 

 took up Gaillon's researches in detail (which had 

 hitherto been but little known) and published the re- 

 sults in the "Diet. d'Hist. nat," art. Nemazoaires. 

 Bory de St. Vincent (1825) founded, in the Arth- 

 rodien, a new natural kingdom, the Doppelseelen 

 (twofold nature) ; Psychodus (it ought properly to be 

 called Dipsychica), the members of which became by 

 turns, plants and animals. Agardh (1827) separated the 

 genera Micromega, Licmophora (Echinella Homceo- 

 cladia?), and Oncobyrsa, and placed them in the family 

 of the Diatomeae, and removed the Micrasterias to the 

 Ulvaceae. Leiblein (1S27) also approved the placing 

 the Bacillaria with the Algae, and placed the genus 

 Closterium with the Diatomeae. Greville, in 1827, 

 constructed his genera Exilaria (Echinella), Monema 

 (Naunema), and Berkeleya (Naunema). Turpin 

 repeated, at Dieppe and Havre, Gaillon's observations, 

 but without confirming them ; he, moreover, asserted 

 Girodella comoides (Schizonema Grevillei) to be 



simply a plant, and the enclosed animals (the 

 navicular bodies) some kind of vegetable matter 

 (Globuline) which he called Naviculine. Sprengel 

 (1827) contended that Achnanthes, Frustulia, Meri- 

 dion, and Gloionema, were the eggs or young of 

 animals, and the genus Diatomeae which he had 

 formerly placed, together with Fragilaria and 

 Schizonoma, with the plant he now considered to 

 be equivocal (zweideutig). 



( To be continued.) 



RESEARCHES IN POND LIFE. 



I MADE a discovery in my tank on the 17th of 

 February which I think worth bringing under 

 the notice of your numerous readers, in the hope that 

 it may lead to some further remarks by those en- 

 gaged in observations and research in pond life. 



Having promised to exhibit a few living specimens 

 at an inaugural meeting of a new microscopical 

 society, I was searching my tank for Stephanoceros, 

 Vorticellae, &c, and fished up from the bottom a 

 small piece of filamentous Algae, upon which I ob- 

 served some minute organisms, and supposed them 

 to be a colony of Floscules. Such a lucky catch I 

 hardly expected, and bottled them up accordingly as 

 beautiful objects to exhibit ; but upon placing them 

 under the microscope I found they were a cluster of the 

 singular organism called the Acineta, attached by their 

 stems all along the filament, as shown in fig. 51. 



Now this organism is one, I believe, to which 

 some interest attaches, from its being but rarely met 

 with. It is figured and described by Mr. Gosse in 

 his admirable work, and he states it to be a stage in 

 the life-history of the Vorticellae, but I must say I 

 have had some doubt upon the point, for hitherto I 

 have never found it associated with any of the species 

 of Vorticellae that have come under my observation 

 during the many years I have devoted to researches 

 in pond life in most of the suburbs of London. In 

 this case, however, it seemed to bear out Mr. Gosse's 

 statements, for, to my great surprise, on one filament 

 of the Algae I found a group of Vorticellae of the 

 Epistylis species, attached by its stem and branching 

 out in the form of a tree. The stem and branches of 

 this species are rigid, and on the tips of some of the 

 branches were the cup-shaped Vorticellae with the 

 fringe of cilia round the mouth, and on others the 

 Acineta, as shown at fig. 52. 



This to me was a singular and striking discovery, 

 and fortunately I had taken the specimen to show my 

 friend, Mr. Badcock of the Royal Microscopical 

 Society, and we spent some time in closely examin- 

 ing it, for, as above stated, previously to the dis- 

 covery of this group we had noticed that the Acineta 

 were attached singly along the filament, and that at 

 intervals there were two or three Vorticellae grouped 

 together and attached to the weed also (see fig. 51 a), 



