1894.] Attraction-Spheres and Centrosomes. 451 
fe . 
ia aa agin from this nucleus; and in the endo- 
ce ee t em in the microsporangium of Isoetes 
ai igium of Polypodium and of Asplenium. 
Dettny facts ensive report (II) he adds many new and in- 
Dr .... apm numerous illustrations of the appear- 
um co Lilium Martagon, Listera ovata, Le- 
| Samii alanthus nivalis. Biitschli found very 
ew a.,, s in Surirella, a large form of diatom. E. 
an (32) has found the attraction-spheres and cen- 
trosomes i i ; : 
Sin Spirogyra jugalis and nitida, and in the spore- 
mother-ce . 
of the oi ot ea both in resting and division stages 
Metis in Be oe (25) claims to have found cen- 
but no aM e sexual cells of Marchantia polymorpha, 
the tiers surrounding them. He found 
chrysophylla, a 3 eres in the antheridia of Gymnogramme 
foetida, Thus nd in the spermatozoids and the ova of Chara 
directly << a a reproductive cells of plants, and those 
éatrosomes ag , the presence of attraction-spheres and 
ee vecorted i. non quite generally demonstrated, but has 
Be egetative cells in but two cases. 
Investigation. 
The r 
Was eal ny, ork on centrosomes and attraction-spheres 
Were principal! ovember, 1893. The growing tips of roots 
Nn other plant : _used, though investigations were also made 
tioning was issues. All of my material which needed sec- 
imbedding noah according to the ordinary, methods, by 
the slide: leapt and afterwards staining the sections on 
quite de I also did some staining 7m toto. After 
of advantage is exper imenting, several methods were found 
i D> he these bodies. — Hermann’s method, 
aks Zimmermann’s ‘‘Die botanische Mikro- 
via r al used very successfully on the root tips of 
. =e e€ centrosomes are ines re black while 
“*omewha : clear, though sometimes 
Mig Bae tet by the safranin. The dark granular limit- 
ted, well defined, while the surrounding cytoplasm is 
Ms days in a ? for one or 
Chloride, on solution of fifteen parts one per cent. platinum 
aoa € part acetic acid, two to four parts two per cent. 
» eighty parts water. Now wash t 
Ing w 
ater, harden gradually in alcohol, , an 
; flowin 
he objects in 
d after that 
eel 
