Damping Off. 325 



pressure. The wall now becomes brown in color and the glomerule 

 appears to be mature. 



In this condition if these hyphal masses are teased out from the 

 •cell of the prothallium and kept on a glass slip in a small amount 

 of moisture germination soon takes place. Hyphal masses so teased 

 ■out from the prothallium and placed under the above conditions at 

 5 p, m, on February 22, 1894, and kept at the ordinary room 

 temperature during the night, the temperature falling somewhat 

 below that of the day (the temperature was 70° to 80° Fahr., up 

 to midnight and fell 30 toward morning and rose to Q6 at 9 a, m.). 

 At 9 a. m. February 23d, the preparations were examined and the 

 mature hyphal masses were germinating. In some cases the germ 

 tubes were 500^ to 700// long and all the protoplasm had moved 

 out in the distal half of the tube (Fig. 42). In germination under 

 such circumstances a protuberance arises from one of the indi- 

 vidual cells of the glomerule and extends soon into a tube the 

 <liameter of which is about 10//. As the tube extends in length the 

 protoplasm gradually disappears from the parent cell and passes 

 into the tube. As the tube continues to elongate the protoplasm 

 continues in the distal portion and the older portion of the tube 

 becomee empty, nothing remaining but the wall. There appears to 

 he a wall at the junction of the tube with the parent cell, if so, it 

 is formed after the protoplasm has passed into the tube. When 

 the tube has become considerably elongated so that there is an 

 empty portion from 200// to 500// in length there appear what 

 seem to be transverse septa, or it may be the remains of a portion 

 of the protoplasm situated in a thin transverse sheet in the tube. 

 These occur so regularly and at about 30/y to 40// distant that the 

 resemblance to septa is very striking if they are not really septa. 

 If they are septa they are formed only after the protopalsm has 

 passed these points. It may be that the growth of the tube was 

 arrested for a certain length of time and the walls were formed 

 while it was in this quiescent condition, or the growth of the tube 

 may be naturally periodic. The protoplasm is coarsely granular, 

 presenting here and there rather faint vacuoles, but there are, so far 

 as examined, no septa separating the protoplasm into distinct por- 

 tions. The course of the tube is slightly sinuous, and also in an 

 ascending position as the glomerule lay on the glass slip. Perhaps 

 this was for the purpose of emerging from the water. After an 

 examination the cultures were returned to the moist chamber. 



