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MONTGOMERY. 
[Vol. XV. 
large nucleolus, with a large vacuole ; he believes that subse¬ 
quent to the two-nucleolus stage one of the nucleoli is extruded 
from the nucleus. Two nucleoli were observed also in the ova 
of Amphicteis , Sanytha , and Melinna. 
Flemming (’97) recurs to the controversy between Korschelt 
(’ 96 ) and Meves (’97), and agrees with Meves that the macro- 
somes are nucleoli, and the microsomes chromatin granules. 
He also mentions the following observation on the ovum of 
Ascidia ca?iina: here there is one “ Nucleolus ” and one much 
smaller “ Kernkorper ” ; “ beobachtet man ihn [Kernkorper] 
am lebend entnommenen Ei, so findet man ihn so gut wie 
stets in Molekularbewegung, und zwar oft in recht grossen 
Exkursionen.” 
Hacker (’97a) (’96 is a preliminary communication), cleavage 
stages of Cyclops brevicornis. This paper deals particularly with 
the “ intraspharale,” “ extranucleare,” or “ Aussen-Kornchen 
(Ektosomen) ” found in certain of the astrospheres of the 
cleaving ovum. These ectosomes are small spherical bodies of 
various size, which stain like the nucleoli, but somewhat more 
intensely. In the resting stage of the cell there are several 
nucleoli in the nucleus, and no ectosomes outside of it ; when 
the nucleus enters on the aster stage, the nucleoli have disap¬ 
peared and ectosomes are present in one of the astrospheres, 
at first at the base of, subsequently on the whole periphery of, 
the latter ; towards the close of the metakinesis there appear 
in the place of. the ectosomes larger clumps of red-staining 
substance. He concludes : “ So glaube ich es denn mit Sicher- 
heit aussprechen zu diirfen, dass diese groberen Brocken auch 
genetisch mit den Kornchen [Ektosomen] zusammenhangen, 
sei es, dass sie direkte Umwandlungsprodukte derselben, sei es, 
dass sie Neubildungen sind, welche dem namlichen Process 
ihre Entstehung verdanken, aber in Folge der wahrend der 
Theilung eintretenden Zustandsanderungen der Zelle eine etwas 
andere Beschaffenheit, einen anderen Aggregatzustand ange- 
nommen haben. Wie ich gleich hier hinzufiigen mochte, ver- 
schwindet die Erscheinung, sowohl im Zweizellenstadium als in 
den spateren Stadien, wahrend der eigentlichen Ruhepause 
vollstandig, indem vermuthlich jene Massen einer Resorbtion 
