180 iVIorphologie, Teratologie, Befruchtung, C5^tologie. 



larger nucleoli. The nucleolus usually has at least one papilla until 

 its disappearance at the metaphase. 



The chromatin in the young microspore mother cell occurs in 

 the form of granules or chromomere aggregates (the chromomere 

 is here considered a chromatic unit). 



There is no presynaptic reticulum, leptonema or zygonema. 

 The chromatin granules are held in an indefinite linin mesh. 



Synapsis is reached b}^ a contraction of the linin supporting 

 structure drawing the chromatin granules together. 



The chromatic Clements emerge from synapsis in the form of 

 a spireme which soon becomes double. 



The spireme shortens and thickens. Transverse segmentation 

 of the spireme results in the Formation of long paired chromosomes 

 which continue to shorten and thicken, producing the characteristic 

 gemini of diakinensis. 



The Separation of homologous chromosomes at the metaphase 

 proceeds as usual. At this stage the chromosomes frequently show 

 a split preparatory for the second division. 



At the telophase a nuclear membrane appears. During interki- 

 nesis the chromatin is in the form of a band, apparently wound 

 about the periphery of the nucleus. The band seems to be split or 

 slightly vacuolate. 



With the formation of the spindle of the second division the 

 nuclear membrane disappears and the chromatic band resolves into 

 chromosomes. 



At the homotypic metaphase the longitudinal halves of the 

 chromosomes separate. 



The method of reduction in Smilax herbacea essentially coinci- 

 des with the "heterohomeotypique" scheme of Gregoire. 



The persistent chromatic body in Smilax is a smaller unit than 

 the chromosome. 



The pairing of chromatic bodies was observed in the prophase, 

 but not as a universal phenomenon. The same condition was evi- 

 dent in the nuclei of the nucellus. 



An efifort to find a sex determinant in Smilax was futile. 



M. J. Sirks (Haarlem). 



Heusser. K., Die Entwicklung der generativen Organe 

 von Himantoglossum hircinum Sprengel [i= Loroglossiim hir- 

 cinum Rieh.]. (Beih. Bot. Cbl. 1. XXXII. p. 218—277. 1915.) 



Die Untersuchungen des Verf. an Hitnantoglossum hirci}ium be- 

 treffen 1) die formale Entwicklung der ßlütenteile mit besonderer Be- 

 rücksichtigung ökologisch wichtiger Organe, und 2) die zytologische 

 Entwicklung der generativen Organe: die Entwicklung des Pollens, 

 der Samenanlage und des Embryosacks, die Befruchtung und die 

 Entwicklung des Embryo. Fixiert wurde meist mit 70%ioem Alko- 

 hol, gefärbt mit Hämatoxylin Delafield— Eosin— Bismarckbraun 

 nach der Ernst'schen Methode. Die Resultate dieser gründlichen 

 Untersuchungen lassen sich am besten und kürzesten mit den 

 Worten des Verf. zusammenfassen: 



1. Hinsichtlich der Morphologie. Die Anlage der Blüten- 

 organe in entsprechenden Kreisen erfolgt ungleichseitig; die Abnor- 

 mität scheint durch die Deckblattanlage mechanisch verursacht zu 

 sein. Die Anlage der Staminodien ist ursprünglich medio-dorsal. 

 Ihre Lage ist für das Diagramm nicht einwandfrei zu verwenden. 



