1900] MICROSCOPICAL JOURNAL. 105 



other organisms, higher still, that the impregnation may 

 take place more than once a year. In fact, I noticed that 

 the Bacillaria were more common in California than in 

 this region, and therefore they multiply more commonly. 

 In the tropics, they must be more common still, and as 

 they there grow or multiply more rapidly, the accumula- 

 tion of their dead shells must be greater. Infusorial de- 

 posits must be greater there also. 



As the minute Nitzschias appear in spring as oval forms 

 they grow to be bigger, but as they have begun to enlarge 

 more in one diameter than in the other, they continue to 

 grow in that manner and one diameter grows much more 

 rapidly than the other. In this manner they became more 

 and more rod-like, until the form is seen of a true Synedra 

 with the longitudinal length several times as great as the 

 transverse one. 



How the other various forms of Bacillaria are formed 

 can only be surmized for it cannot at present be seen how 

 it takes place. But how a round form like Coscindiscus 

 can change into a five or six-sided form and this into one 

 four-sided,(Ampliitetras) or a three-sided (Triceratiura)or 

 even a two-sided form (Biddulphia) can readily be seen. 

 Already they are all placed in one genus, but there are 

 forms that it is difificult to see how they came about. Time 

 will unravel that seeming mystery, as it has other equal- 

 ly hard ones, and the evolution of the Bacillaria be made 

 plain. 



I wish to make plain so far as possible the synonomy 

 of the Bacillaria for the study of those beautiful atomies 

 should be made as easy and as pleasant as possible. It 

 must be remembered that study is very different from 

 observing and naming. Anyone can observe and name a 

 thing but only one who spends time to observe can study 

 the things he sees. 



In the report on diatoms of H. M. S. ''Valorous" which 

 went on a cruise to Davis Straits in 1875, (jeorge Dixie 



