232 THE AMERICAN MONTHLY [July 



is thrust out ahead, and the case is dragg^ed up to it and 

 adheres by its roug-hness until the body can be ag-ain 

 thrust forward about half its leng-th, when the case is ag-ain 

 '•hitched" forward. The masticated wool may be seen in 

 the intestine ; the pieces are liberal in size, which seems to 

 indicate a very robust dig-estible tract. A mass of stored 

 up fat may be seen at the posterior extremity of the body. 

 This worm is able to make muscle, fat, blood and moisture 

 out of the dr}' wool fibres. S. G. S. 



Bog Moss Leaves. — The bog- mosses are widely distri- 

 buted in cooler climates, being the chief source of peat and 

 turf deposits. They keep moist for very long periods, 

 preserving: the water in the bog-s when the surrounding- 

 country is completely dried up. The cells of the leaf are 

 of two kinds: (1) narrow elong-ated cells filled with chloro- 

 phyll, the so-called ducts, and(2)larg-e empty cells stiffened 

 by spiral or annular thickening-s, and perforated by larg-e 

 pores which communicate with the exterior. These large 

 cells are called the utricles; they retain the water for a 

 g-reat length of time, and serve as homes for various 

 w'orms, rotifers, amoebae, etc., some of which may be seen 

 in a slide. A. P. Brown. 



Statoblasts ("winter eggs") of Pectinatella. — These 



are not eggs, since they cannot be traced to a single cell. 



A statoblast is formed by the separation of a mass of cells 



within the tissue of the Bryozoan ; this mass cannot be 



traced back to any one cell, hence it is not an eg-g, or a 



developing egg, but is to be reg-arded morphologically as 



a bud, an internal one to be sure, which surrounds itself 



with a thick double cellular coating-, and passes the winter 



in this shape. The^tatement in most text-books that the 



statoblasts are parthenogenetic eg-g-s has been absolutely 



disproved. If at the time when they are beginning to form, 



transverse sections be made, of the colony, these cell 



masses may be clearly made out in the funiculus, and the 



stag-es in their formation may be follow^ed. 



Henky B. Ward. 



The \A^ater Mites (^Hydrachnidae), — These acquatic 



