20 THE HANCOCK !>.\tll IC EXPKDITICINS VOL. 3 



Professor Froiny locordod some excellent observations, well il- 

 lustrated, and duplicated in our material, on the fragmentation of 

 filaments of Johannesbaptistia by the death and disintegration of 

 cells within the filaments. This mode of vegetative reproduction 

 reminds one forcibly of production of hormogonia among the Oscil- 

 latoriaceae. It, together with the uniseriate arrangement of cells in 

 the tilanient, leads Professor Frcmy to suggest that Johannesbaptistia 

 is closely related to the genus Oscillatoria and should be placed at 

 least tentatively between that genus and Lyngb^a in a natural 

 scheme of classification. Professor Fremy also compares filaments 

 of Johannesbaptistia with filaments of a species of Lyngbya in 

 which the colls are separated from each other. It has been my ex- 

 perience that separation of cells in any filaments of the Homo- 

 cysteae is also accompanied by other pathological characteristics — 

 loss of pigment, change in shape of cells, and production or loss of 

 protoplasmic granules. In filaments of Oscillatoria or Lyngbya with 

 separated cells, the cylindrical sheath about the trichome is always, 

 as 1 have observed it, distinctly limited from and of a firmer con- 

 sistency than the more recently formed jelly between the cells — 

 if indeed such jelly can be demonstrated. We may as rightfully 

 transfer at once to the Hormogoneales any of the Entophysalidaceae 

 or Pleurocapsaceae as soon as a filament has been seen to break 

 into segments because of death and disintegration of a cell within 

 a filament. It is to be remembered that as yet J ohannesbaptistia 

 prlmarui is known in only the few bits of preserved material listed 

 above and that the complete life-history of the organism is possibly 

 not represented in any of these. Observation of one tiny aggrega- 

 tion of filaments in our No. I2j from the Galapagos Islands leads 

 me to suppose it wholly probable that when more favorable material 

 presents itself in the future — perhaps a collection containing an 

 abundance of filaments aggregated into a gelatinous stratum — divi- 

 sions of the cells in planes other than at right angles with the axis 

 of the filament may be observed. The above I suggest as a possibility, 

 as likely to be found correct as the Impossibility of division of cells 

 in se\eral planes implied when the genus Johannesbaptistia is placed 

 in a taxonomic scheme between Oscillatoria and Lyngbya. I suggest 

 that Johannesbaptistia primaria (Gardner) J. deToni be allowed to 

 stand appended to the Chroococcaceae until further and more eluci- 

 dating studies have been made. 



