632 SUMMARY OF CURRENT RESEARCHES RELATING TO 



by chemical and physical disintegration, partly by the active agency of 

 the elements of the follicular envelopes. This is described at length. 

 The result is the same as before — the specific epithelium of the follicle 

 is wholly lost and the remains of the connective-tissue pass into the 

 lamina ovarii superficialis. 



Albuminoid Crystals in Ova of Roe Deer. * — V. von Ebner de- 

 scribes the remarkable occurrence of crystalline bodies in the ova of 

 the roe deer. The reactions point to an albuminoid body, insoluble in 

 water, soluble in salt solution,— a globulin in the strict sense. The 

 crystals occurred only in ova already surrounded by a zona. 



Ovary and Menstruation.! — J. Halban has made experiments on 

 Pavian monkeys which have led him to the conclusion that menstruation 

 is definitely stopped after removal of the ovaries. The experiments 

 show that menstruation is dependent on the ovary ; and that the cause 

 of menstruation is to be found in a chemical, not directly nervous, nexus, 

 since the persistence of menstruation depends on the presence of the 

 ovary in the body irrespective of its position, whether subcutaneously 

 between muscle and fascia, or in the mesentery. 



Pseudochromosomes in Ova of Birds.J — F. d'Hollander describes 

 " pseudochromosomes " (" Balbiani's nucleus," " vitelline nucleus ") in 

 the ova of Parus major, Muscicapa grisola, and the fowl. These bodies 

 occur in varied form (as granules, rods, filaments, vesicles with chromatic 

 walls, &c), distinct from the germinal vesicle. He regards these enig- 

 matical bodies as equivalent to the " pseudochromosomes " of Heidenhain 

 and Piirst, the ergastoplasmic structures of Prenant and the brothers 

 Bouin, the spicules found by von Winiwarter in the human ovum, and 

 the pseudochromosomes observed by Van der Stricht in the ovum of 

 the bat. 



Atypical Spermatozoa.§— I. Broman has studied the atypical forms 

 of spermatozoa occurring in man, salamander, and dog-fish. He dis- 

 tinguishes three sets : — (I.) Giant and dwarf spermatozoa occur which 

 are typical except in size. They probably arise from spermatocytes 

 whose chromosomes have been unequally divided between the two 

 daughter-cells. (II.) Spermatozoa occur with 2-4 tails but one head, 

 which arise from spermatocytes with bipolar or multipolar mitoses. 

 (III.) Spermatozoa with two or three heads also occur, and arise in 

 man when nuclear division of spermatocytes is not followed by plasmic 

 division. In the forms of this type which occur in the salamander the 

 behaviour of the idiozome is of particular interest. 



A fourth category of atypical spermatozoa is elsewhere || discussed. 

 It includes those (often occurring in man) which have au abnormal form. 

 The abnormality may affect the form of the head, the attachment of the 

 tail, the spiral sheath of the connecting-piece, or the sheath of the main 

 tail-piece, or several of these at once. The origin of these abnormalities 

 is unknown, — perhaps they may be classed as pathological variations. 



* SB. Alcad. Wiss. Wieu, ex. (1901) pp. 5-12 (2 figs.). 

 t Tom. cit., pp. 71-92. 



t Yerh. Anat. Ges., xvi. Vers, in Anat. Anzeig. Erg'anzungshft., xxi. (1902). 

 pp. 16S-71 (5 fiss.). § Anat. Hefto, xviii. (1902) pp. 509-47 (11 pis.), 



|| Anat. Anzeig., xxi. (1902) pp. 497-531 (107 figs.). 



