i. Fortpflanzungslehre. 559 



animal niay break oft' small Fragments from the egg, which have been Been to 

 onite again with the egg after moving freely aboul the cavity. The oocyte 

 prepares for its maturation beforo it has acquired all its yolk, and although 

 several large eggs may be present only one andergoes maturation at a time. 

 The nucleus breaks down, the chromosomes appear, and the amphiaster of tbe 

 first polar body appears. At first it is small, but it grows with tbe growth 

 of the egg, so that by tbe time tbe egg has reached its füll size the spindle 

 ig three times as long as it was at first. Wbou tbe amphiaster has reacbed 

 its füll development, il remains in this condition until the egg is laid in sea- 

 water. If tbe conditions are unfavourable it may remain in tbe same con- 

 dition for nearly a weck, with spindle and astral rays unchanged. The spindle 

 measures 50 — 60 fi in length; on tbe wbole it lies along the long axis of tbe 

 egg, but as tbe egg cbanges its form tbe spindle varies in its position. The 

 astral rays are less definite than the spindle-fibres, and appear as tbrcads 

 boaring granules running between the yolk-grains. The chromosomes are 

 arranged round the periphery of the equatorial plate, and are eigth in number. 

 Each lies against a spindle fibre, but they have no proper mantle-fibres ; t he 

 spindle-fibres number twenty. The spindle-fibres appear to be at least in part of 

 extra-nuclear origin, and the centrosomc clearly arises outside the nucleus. 

 The Spermatozoon enters the egg before the amphiaster appears, but fusion 

 of the pronuclei takes place only after the polar body is extruded, in sea- 

 water. A remarkable Observation clearly proves the semi-solid nature of tbe 

 spindle. If the animal is compressed the body-wall may be ruptured and the 

 egg bursts out into the water. The yolk-granules disperse in the water, 

 leaving the spindle and asters free, when the wbole amphiaster can be seen 

 rollicg over and over as it is pushed along by the granules. It persists for 

 some minutes, and gradually dissolves, the asters disappearing first and the 

 central spindle later. In one case the separate threads of the spindle could 

 be seen, some of them broken and with yolk-granules entangled among them. 



Doncaster (Cambridge). 



1170) Curtis, M. R. (Maine Agr. Exp. Stat Orono-Me.), The ligaments of 



the oviduct of the domestic fowl. 



(Anat. Anz. 36.18. p. 472—476. 1 Abb. 1910.) 

 Von besonderem Interesse sind die Ausführungen Verf. über den Mecha- 

 nismus des Überganges der reifen Eier vom Ovarium in die Oviduktmündung. 

 Dieser Transport ist bei den verschiedenen Wirbeltierklassen in der verschieden- 

 sten Weise gesichert. Beim Huhn steckt das Ovarium der legenden Benne 

 praktisch geradezu in einer Tasche, die vom Peritoneum umwallt und gegen 

 die übrige Bauchhöhle abgeschlossen ist. Mit mechanischer Notwendigkeit 

 gehen die entleerten Eier in die Öffnung des Oviduktes hinein. An der Um- 

 wallung beteiligen sich der linke abdominale Luftsack sowie ein Teil des 

 Mesenteriums und des Darmes. Nur ein schmaler Raum bleibt übrig dorsal 

 an der Vereinigungsstelle des linken Cöcums und des Rektums und lateral von 

 diesem. In diesem Raum liegt nun gerade der Tubenmund. Pol! (Berlin). 



J171) Saxton, W. T. (Bot. Lab. South Africa College Cape Town), Con- 



tributions to the life history of Widdringtonia cupressoides. 



(Bot. Gazette 50,1. p. 31— 48. pl. L-3. 3 Fig. 1910.) 



Von allgemein interessanten Resultaten der cytologischen Untersuchung 



bei genannter Konifere wäre zunächst zu erwähnen, daß an der Basis des 



Nucellus sich ca. »5 1 Megasporen-Mutterzellen ausbilden, von denen indes nur 



eine sich weiter entwickelt. In den in Luhe bleibenden zeigten sich beson- 



