Developmeiit of ttie Bacillaria from 

 ao aieboid forni and formation of that amoeboid forni by energenesis 



BY ARTHUR M. EDWARDS, M. D. 



The time has come for making public some things that I seen 

 several times for several years. The main facts that I shall herein 

 record were made in the year igoS but they lead up to observations 

 made and recorded fifteen or twenty years back and kept by them- 

 selves without publishing them at ali. 



I will therefor speak now of the Bacillaria which appear first 

 in spring bere in Newark, New Jersey. These I bave observed for 

 years in the soil, which is clayey, and also later in the streams, 

 brooks, rivers and in marshes and standing waters. The soil is 

 damp, but not watery, the day' makes it damp from the molti ng 

 snow which now disappears. I made these observations in Newark, 

 New Jersey because I reside there but they can be repeated else- 

 where by others and 1 think they will be just the same. 



Taking then one of the forms of Bacillaria as a text I shall 

 speak of Synedra quadrangida, F. T. K. This is common in the slow 

 stream in Branch Brook Park the largest public park in Newark, 

 New Jersey. 



I found in on the i6th of October 190Ó in profusion and it is 

 common whenever the Bacillaria are looked for in the early spring 

 scason. It is first formed as an amoeboid form which makes its ap- 

 pearance to the aided eye with a 400 magnifìcation which is the po- 

 power of a V4 of an inch of Spencer' s make which 1 commonly 

 use in searching over my gatherings. It is formed by energenesis, 

 which is the term I usually employ and which may be another name 



