2412 Journal of Applied Microscopy 



on a covered glass and watched with the microscope. Very soon a great num- 

 ber of the cells began active motion, escaped from the jelly (which was very 

 thin) and hurried away to the dark side of the glass, where they crowded each 

 other in great numbers. The swarm spores show every variation in size, and it 

 is difficult to distinguish the smaller of them from gametes. 



In studying the algae, notes should be taken on their periodicity — time of 

 appearance and disappearance in any given place. They show periodicity very 

 strongly, and repay observation along this line (See Fritsch. Algological Notes, 

 IV. Remarks on the Periodical Development of the Algae in the Artificial 

 Waters at Kew. Annals of Botany, Vol. 17, No. 45, 1903). 



A serious drawback to the use of Rhizopus in class work is the difficulty, 

 often impossibility, of obtaining its sexual reproduction, and a good substitute 

 for it is needed. Such a substitude is to be found in Sporodinia grandis. There 

 is no reason for failure to obtain the zygotes of this form if a little care is taken. 

 Bring into the laboratory a number of moderately firm mushrooms, such as 

 Polyperus or Russula (ones that do not deliquesce), and leave them exposed on 

 the table, if the weather is not too dry. In a day or two Sporodinia is almost 

 certain to appear on some of them as a yellowish flufify growth, changing to dark 

 brown as the zygotes are formed. When obtained, this fungus never fails to 

 produce sexually. During the past fall and winter I have had no difficulty in 

 getting conjugating stages, not only in Sporodinia, but also in Rhizopus nigricans 

 and Mucor hetorogamus. W. C. Coker. 



University of North Carolina. 



Keeping Earthworms Alive in Winter. 



The period for studying the earthworm often comes, in its logical position in 

 a zodlogical course, late in the fall or in the winter, when living specimens can- 

 not be collected. It is therefore necessary, for some parts of the work, to keep 

 a number of specimens alive. This may be done in boxes of earth, but 

 frequently the results of this method are unsatisfactory, especially when a large 

 number of the worms must be kept. If the earth is allowed to become for a 

 short time too moist or too dry, the worms die, and in any case it is difficult to 

 get at them when only one or two specimens are wanted. 



A method of keeping them which obviates these difficulties was used by the 

 writer with much success during the past winter. This is the very simple 

 method which was recommended by Joest (Archiv. f. Entw.-Mech., Bd. 5, 1897, 

 p. 425) for cleaning out the intestine of the earthworm before sectioning. The 

 worms are placed in a tight jar or other vessel, together with a quantity of damp 

 clean cloth. I used bacteria dishes about nine inches in diameter by three 

 inches in hight, covered with a plate of glass. In each dish ten or a dozen 

 worms were placed. Then strips of muslin were wet with clean water, the water 

 pressed out as far as this could be done with the hand, and with these the 

 worms were covered. The cloth must not be dripping wet, but only decidedly 

 damp. The worms were kept in this way more than three months, and were 



