•• 



Miscellaneous. 2V)1 



[ a curious and amusing spectacle to witness the odd little creature 



thus backing the accurately poised impediments out of its domicile, 



\ and then returning to put its house in order once more. The cor- 



rectness of the early observations of M, Bonnet is thus fully confirmed 



\ by Dr. McCook's experiments. — Proc. Acad. Nat. Set. Phrlad., Oct. 



24, 1882, p. 258. 



j 



On the Relations existing between Palmella uvieformis and an Alga 



of the Order Confervacece. By M. J. B. Schnetzlek, 



In May 1881 I observed in a small rivulet near Lausanne some 

 small rounded, bodies of a bright green colour, with a nodular sur- 

 face ; they were attached to the bottom, and presented a gelatinous 

 consistence. These bodies were formed by a small unicellular alga 

 {Palmella uvceformis, Kiitz.), the globose cells of which presented a 

 diameter of about 0-01 millim. They were gelatinized and united 

 in colonies, accompanied by numerous diatoms and crystals of car- 

 bonate of lime. This alga was placed in a glass containing about 

 3 centilitres of spring-water. Besides these colonies of Pal nulla, the 

 water contained no trace of other green Algre. The glass was 

 covered with a watch-glass. 



Two days afterwards there issued from these gelatinized colonies 

 of Palmella zoospores, which, after swimming briskly in the water, 

 attached themselves to the walls of the glass, where they formed a 

 green coating. These zoospores soon began to germinate, and pro- 

 l duced green Algae with branched filaments, the cells of which were 



at first cylindrical, somewhat elongated, with lateral excrescences. 

 I Perfectly identical Algae were developed directly from the gelati- 



nized cells of the Palmella. 



When the water containing these Algee had evaporated to about 

 1 centilitre, the cells of those Algae which presented all the charac- 

 ters of Confervacese acquired a globose form, and, becoming detached, 

 formed new gelatinous colonies of Palmella. This transformation 

 took place at the end of August and the beginning of September. 



Cienkowski* has observed that an Alga of the genus Stigeoelo- 

 nium produces gelatinized cells, which, grouped into colonies, 

 form a Palmella. Famintzin, bv concentrating the solution of inor- 



I > ganie salts of the nutritive liquid, succeeded in producing the dis- 



aggregation of a Stigeorfonium and of another Confervacean into 

 cells of Protococeus. The numerous observations of Cicnkowski 

 support the opinion, already expressed by Kiitzing and others, that 

 the Palmetto Protococc and Pleurococci are only phases of deve- 



j lopment of different Confervaceous Algae. ■ 



The observation that I have just noted completes those of Cien- 

 kowski. The learned Russian botanist has seen a Confervacean 



f become transformed into a Palmella^ whilst 1 have observed the 



transformation of a Palmella into a Confervaceant. 



* Instit. Bofc Jahresb. 1876, pp. 42 18. 

 t Stigeodonmm or an allied form* 



