Fossombronia longiseta , A ust. 97 
stain with marked avidity. In all cases examined the blepharoplast first 
appears in the cytoplasm, but no light can be thrown upon its origin. 
Much time was devoted to the study of this particular question, but without 
result. Shortly after the appearance of this structure it is seen to migrate 
towards the more acute angle of the spermatid, which in some cases faces 
the similar angle of the sister cell, though usually they are seen to lie 
as represented in Fig. 24, Ph V. At the completion of migration the 
blepharoplast is seen to occupy the angle above mentioned, and appears 
closely applied to the cell membrane. Previous to this, however, there 
also appears in the cytoplasm another and considerably larger, dark- 
staining body, reported for the first time in the Hepaticae by Ikeno 
in his studies on the spermatogenesis in M arc hantia poly morpha. It seems 
that Strasburger and Guignard have not reported such a structure in the 
plants studied by them. To this body Ikeno gives the name ‘ Nebenkorper.’ 
Its behaviour in the spermatid of Fossombronia is somewhat different from 
that in Marchantia. It appears in the cytoplasm, Fig. 26, PI. V, without 
reference to any definite position, though usually it is found occupying 
a position not far from the nucleus and between the nucleus and the 
blepharoplast, which, by the time of the appearance of the ‘ Nebenkorper,’ 
has nearly completed its migration to the pole. Invariably this accessory 
body seems to seek a position just beneath the blepharoplast, where it is 
seen to elongate. Ikeno 1 states that shortly after the cilia have started to 
grow the ‘Nebenkorper’ in Marchantia vanish. Thus, according to his 
description, this structure plays no part in the formation of the sper- 
matozoid, though his figures seem to show an elongation of the ‘Neben- 
korper,’ and the ultimate passage of the same into the structure of the 
spermatozoid, apparently forming the middle piece. Further on, however, 
he states (p. 79) ‘ der cytoplasmatische Forsatz beginnt sich auszubilden 
und wachst nach der Richtung des vorderen Endes des jetzt sich bildenden 
Spermatozoids hin, um schliesslich das Zentrosom zu erreichen, so dass 
dieser Forsatz den letzteren mit dem Zellkern verbindet.’ In Fossombronia 
several preparations were obtained, showing the attenuation of the ‘ Neben- 
korper ’ as represented in Fig. 29. At this stage, Fig. 30, PL V, or a little 
before, the cytoplasm is seen to elongate in the direction of the ‘Neben- 
korper ’ and blepharoplast, apparently connecting with the former, which in 
its elongated form has come to lie close to the plasma-membrane of the 
young spermatozoid. Later the connexion seems to become complete 
as in Fig. 31, PI. V, and then the developing spermatozoid elongates 
rapidly. Previous to the appearance of cilia the blepharoplast elongates 
somewhat (though a number of instances were observed in which this was 
not perceptible), apparently following the inner contour of the cell- 
membrane instead of forming a ‘ Cytoplasmahocker ’ as described by 
1 loc. cit., p. 71. 
H 
