250 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Craspeclodiscus, Auliscus, Pseudoauliscus, Arachnouliscits, Naviculce 

 belonging to the groups Didynife and Lyrse, Cymhella, &c. 



In Gomplwnema Mnstela, the author states that the frustules, after 

 they have become reduced, by repeated division, to the smallest 

 dimensions, leave their pedicel and attach themselves together, in a 

 reverse position with respect to one another, by their ventral sides ; 

 from which he deduces an argument in favour of the animal nature 

 of diatoms. 



In the CymbelleK, in which the reproduction of Cymbella gantroides 

 and Cocconema Cistida is delineated, the author believes that there is 

 also, as in Gomphonema, a distinction between the upper and under 

 part of the frustule ; and supposes that, when conjugating, they also 

 attach themselves to one another in a reverse position. The un- 

 symmetrical arrangement of the cell-contents of several species of 

 Navicula, already pointed out by Pfitzer, is illustrated by drawings 

 of N. dicephala ; and the inference is drawn that all species of 

 Navicula present a difference between the anterior and posterior ends, 

 which is well exhibited in some true Naviculce. The very variable 

 cell-contents of Cocconema lanceolatum and Cymhella gastroides are 

 well illustrated. In Encyonema gracile, the author has detected and 

 drawn some very peculiar moniliform corpuscles (possibly parasites) 

 with a trembling motion in the middle of the frustules. 



" Aphaneri "— Examinatioii of Water.* — The water of the Lago 

 Maggiore, which it has been proposed to convey to Milan, has lately 

 been examined by Prof. Maggi by M. Certes' method,| the samples 

 being taken at 65 m. depth, and about 400 m. from the banks. Forty- 

 eight hours after a little osmic acid was added, there was obtained a 

 small deposit of dead organisms of bacterian form, none of which had 

 appeared in the Microscope. He found a solution of chloride of palla- 

 dium to have also the effect of hardening these small organisms and so 

 making them opaque and microscopically visible. Small irregular 

 masses of protoplasmic nature, capable of taking colour from a 

 magenta solution, were also thrown down. Prof. Maggi further 

 treated the water of the lake with various colouring agents. Hsema- 

 toxylin, methyl-violet, magenta, and Lione blue, gave the best results. 

 While the same small organisms and protoplasmic masses were mani- 

 fested, only the latter, curiously, took the colour. In spring water of 

 Valcuvia, and rain-water, microbes like those in the lake, not visible 

 with a power of 800 diameters, were revealed by the colouring and 

 hardening reagents. 



Prof. Maggi proposes to call these organisms Aphaneri, as dis- 

 tinguished from the bacteria and microbes which, without reagents, 

 are visible in the Microscope (Phaneri), and among which are agents 

 of infection, and which take colour from methyl-violet, magenta, &c. 

 The Aphaneri, he thinks, are probably harmless. 



* Nature, xxv. (1882) p. 348. 



t See this Journal, iii. (1880) p. 847. 



