72 N. H. COWDRY. 



Ceratiomyxa - , Hemitrichia clavata, 



Cribraria - , Lycogala epidendrum, 



Enteridium rozeanum, Stemonitis - . 



They were collected during June, July and August near South 

 Harpswell, Me., and during September, October and November 

 in the vicinity of Baltimore, Md. At South Harpswell, the Di- 

 rector, Dr. Kingsley, very kindly placed the resources of the 

 biological laboratory at my disposal and I wish to thank him for 

 his courtesy. 



Portions of the plasmodia were collected, shortly before spo- 

 rangium formation, on the surfaces of leaves, mosses and damp 

 logs. Immature sporangia were found showing well all the 

 stages between the undifferentiated plasmodium and the young 

 spores. These were placed immediately in the fixative. Smears 

 of the plasmodium were treated in the same manner with results 

 which were only confirmatory, but by no means so distinct or 



i 



satisfactory. 



Fixation: 



1. Pieces not larger than 4 cubic millimeters were placed in the 

 following mixture: 



Commercial formalin 5 c.c. 



(A mixture of formaldehyde, water and methyl 



alcohol should not be used.) 

 3 per cent, potassium bichromate 20 c.c. 



4 to 5 days, changing daily. 



2. 3 per cent, potassium bichromate, changing every second 

 day, 7 to 8 days. 



3. Wash in running water 24 hours. 



This is the ordinary Regaud ('10, p. 296) IVB fixative which 

 can be modified with very excellent results, in some cases, by 

 diluting the fixative with an equal volume of water, applying it 

 for 2 to 4 days only and the bichromate for 3 to 5 days as rec- 

 ommended by Sapehin ('15, p. 321). 



Another very good fixative is Regaud IVA: 



1 . Formalin 10 to 50 c.c. 



Water 50 c.c. 



for i to 5 days. 



2. 3 per cent, potassium bichromate, 3 to 4 weeks. 



3. Wash in running water, I day. 



