Transactions of skction i. 767 



3. The Microchemistry of the Spermatic Elements in Vertebrates. 

 By Professor A. B. Macallum, F.R.S. 



In the heads of the spermatic elements in the frog, guinea-pig, and rabbit 

 practically no evidence of the presence of iron is to be obtained on keeping the 

 alcohol-hardened material in contact with glycerine-ammonium EUlphide reagent 

 at GO C. for days. In the nuclei of the spermatogonia and spermatocytes 

 (rabbit), on the other hand, the chromatin contains 'masked' iron. The 

 chromatin of the spermatids also gives evidenco of its presence, but ill a much 

 lets distinct degree. It is evident, therefore, that in the development of the 

 spermatozoa from the spermatogonia the masked iron is eliminated. 



The hexanitrite of cobalt and sodium applied as a reagent for potassium to 

 the fresh spermatic elements reveals an extraordinary distribution of potassium 

 in the vicinity of the head and in the middle piece. In the frog, as these elements 

 are before their discharge into the duct, potassium occurs in a minute deposit 

 in the cytoplasm at the very anterior point of the head. It is also distributed 

 in the remains of the cytoplasm, as a cap-like deposit, covering the posterior end 

 of the head. In the elements in the higher forms (Homo) it occurs in a more or 

 less concentrated deposit about the posterior half of the head and in the anterior 

 portion of the middle piece. Sometimes the deposit about the head is in the form 

 of a distinct zonular band, sometimes the band is replaced by a zone of large 

 granules, and behind this band there may be some minor or less distinct bands. 

 The latter may also continue as a series into the middle piece proper. No 

 potassium has been found in the posterior third of the middle piece. 



The contents of the head do not contain any inorganic compounds. The 

 potassium about the heads is contained in what would represent a part of the 

 residue of the cytoplasm of the spermatogonium and spermatocyte. 



4. The Afferent Nerves of the Eye Muscles. By Dr. E. E. Laslett, 

 Professor C. S. Sherrington, F.B.S., and Miss F. Tozer. 



5. Qtiantitative Estimation of Hydrocyanic Acid in Vegetable and Animal 

 Tissues. By Professor A. D. Waller, F.R.S.—Sqc Report on Electro- 

 motive Phenomena in Plants, p. 281. 



G. Microphoiorjraphs of Muscle. By Dr. Murray Dobie. 



Joint Discussion tvith Section L on Speech.See p. 816. 



3 d 3 



