40 Transactions of the Sociefij. 



(2) thallus of Coceonema cistula, representiug the corpuscles in 

 various stages of development. Unfortunately the amplification is 

 not stated, a matter of some importance. It is also to be hoped 

 that Dr. Lanzi will make some experiments to test the power pos- 

 sessed by them to resist desiccation without losing their vitality. 

 In Herr Grrunow's " New Diatoms from Honduras," ' M. M. J.,' 

 vol. xviii. p. 184, PI. 196, Fig. 4&, is described and figured a 

 curious abnormity of Gerataulus lievis. Within the large frustule 

 are two very small ones. Herr Grunow asks, " In what manner 

 do these abnormal frustules multiply and reproduce a new series 

 of normal forms? Certainly not by conjugation or self- division." 

 Professor Cleve * figures a frustule of Biddulphia aurita with a 

 small frustule within. In a note (p. 184), I suggested " that the 

 endochrome, under certain conditions, might possess the power of 

 producing (? by means of microspores) perfect frustules without 

 conjugation." Dr. Lanzi's discovery confirms my supposition, and 

 explains the formation of the small frustules within the large one. 



* ' Bihang till Vet. Akad. Hand.,' band i. tab. iv. fig. 3 a 6. 



