142 W. H. LONGLEY 



two eggs may escape from one opening, either on account of the 

 internal rupture of one follicle into another, or by the rupture 

 of a follicle with more than one egg. In the case of animals killed 

 prior to ovulation only the ovaries were removed, while in those 

 killed subsequent to that process the Fallopian tubes, stripped 

 of as much connective tissue as possible, were also preserved. 



As a fixing agent of general utility Zenker's fluid gave satis- 

 factor}^ results. Gilson's fluid and strong Flemming were also 

 employed. After dehydration of tissues with alcohol either 

 cedar oil or xylol was used in preparation for embedding them in 

 paraffin. Those which had been treated with the former seemed 

 less brittle than those upon which the latter had been employed. 

 All sections were cut 0.01 mm. thick and stained in lots of 25 slides 

 in Delafield's or Harris's haematoxylin. For preliminary work 

 this stain was entirely satisfactory, but Heidenhain's iron haema- 

 toxylin was substituted before the study of an important or inter- 

 esting series was considered complete. 



For demonstration of the fatty globules of the cat's egg strong 

 Flemming's fluid was used, and it is a satisfactory^ reagent for 

 the purpose. The fixation of the blackened fat is not permanent 

 however, and to stand a very few minutes in a mixture of benzole 

 and turpentine will completely remove it. Since Delafield's 

 haematoxylin does not stain well when the tissue is preserved in 

 Flemming's fluid, this fixing agent was used only sparingly and 

 for the specific purpose of studying the fat globules or spindle 

 fibres, which are perhaps a little better indicated through its 

 use than through that of Zenker's fluid. 



In the endeavor to relate to one another the different stages 

 of degenerating eggs found abundantly in almost any ovar}^, or 

 to distinguish between normal and abnormal eggs, Mallory's 

 connective tissue stain was found to be of great service. Although 

 its action is a little uncertain, that is to say, although in different 

 ovaries the same element, the granulosa cells for example, is not 

 always stained exactly the same color, upon a number of slides 

 preserved in the same way and subjected together to the stain for 

 the same length of time its action is accurate. It stains the 

 follicular fluid of different follicles in a perfectly specific way, 



