76 



Proceedings of the Royal Irish Academy. 



repulse the male. Since normal animals only copulate when on heat, the 

 conclusion is drawn that this follicular hormone is the cause of oestrual or 

 mating instincts. 



3. Several injections of the extract were made into animals after weaning 

 at the age of three to four weeks. They became sexually mature in two to 

 four days, or at least twenty days to forty days too soon. These experiments 

 were done with controls. 



4. Parallel results were not obtained with corpus luteuni extract and 

 commercial ovarian extracts. 



5. The authors conclude that this new extract is produced under the 

 influence of the maturing ova by the follicle cells : and since the extract 

 was obtained from hogs, and works on rats and mice, it is not specific for 

 any species. 



IV. — Technique. 



Obviously the surgeon's assistant could not be bothered with the large 

 number of fixing fluids used when studying the lower animals, and it was 

 necessary to restrict the number of bottles of fluid to two. The two modern 

 fixing mixtures which I have found most suitable for after-treatment by a 

 variety of methods are those of Da Pane (cobalt nitrate formalin) and of 

 Eegaud (chromeformalin). The appended table gives the various after- 

 treatments. Under the Da Fano method 1, 2, and 3, one gets the Golgi 

 apparatus ; under 4, Golgi apparatus dissolved away, and an ordinary iron 

 haematoxylin stain ; as also under 5. By method 6 ( Sjovall) one gets 

 mitochondria or lutein granules, and sometimes Golgi apparatus as well. 

 Under 7, one gets mitochondria (10) fat and lutein granules (8 and 9), and 

 general stains, 11 and 12. 



Mann's methyl blue eosin, and safranin and light green, after Da Fano 

 sections toned, gave splendid results. 



Fixation in two Lots. 



1. Da Fano's Fluid. 



-J i L 



5. Continued, after two 

 days' fixation, lo 

 sections and iron 

 haematoxylin. 



2. Da Fano method 

 earned out. 



vl/ 



6. Washed in water and 

 post-osniicated ;ind 

 mounted, suiined or 

 unsl^ined. 



si/ 



Toned and stained 

 in safranin and 

 light green. 



Silver extracted by 

 iron alum haema- 

 toxylin stain. 



1 



vl/ 

 7. lIuUer-Forraol. 



I 



S. Schridde. 



L 



10. Reguad. 



9. Post-osniicateil. 



^ 



11. Altmanii. 



Si/ 

 12. Iron haematox- 

 ylin. 



