No. 396.] REVIEWS OF RECENT LITERATURE. 973 
tissue cells: Objects, stamen hairs of Tradescantia, epidermis of 
larval salamander. Second Day, Unicellular organisms: Objects, 
Amceba, Pelomyxa, Stylonichia. Third Day, Resting nuclei; nuclear 
reticulum and nucleoli: Objects, living nuclei from the urinary 
bladder of Salamandra, ovarian eggs of Siredon and Triton. Fourth 
Day, Chemistry of the cell nucleus: Objects, sperm of salmon and 
trout, leaf epidermis of Leucojum. Fifth Day, Physiology of the 
cell nucleus: Objects, Stentor, root hairs of seedlings of pea, egg 
tubes of Dytiscus. Sixth Day, Cell division, (2) Chromatic Figure : 
Objects, epithelium from cornea and tail of larval salamander, 
peripheral protoplasmic layer of the embryo sac of Fritillaria, testis 
of salamander, Seventh Day, Cell division, (4) Achromatic Figure: 
Fertilized eggs of Ascaris, uterine eggs of Thysanozoon. Eighth 
Day, Centrosomes: Objects, eggs of Cyclops, pigment cells of the 
corium of the pike, winter eggs of Sida. Ninth Day, Oogenesis, (a) 
Germinal Vesicle: Objects, ovary of Canthocamptus and of other 
fresh-water copepods. Tenth Day, Odgenesis, (4) Germinal Spot 
and Yolk Nucleus: Objects, ovarian eggs of fresh-water mussel, 
fertilized eggs of Myzostoma, ovarian eggs of Tegnaria and Pholcus. 
Eleventh Day, Odgenesis, (c) Polar-body Formation: Objects, ferti- 
lized eggs of starfish, uterine eggs of Ascaris. Twelfth Day, Sper- 
matogenesis: Objects, sperm tubes of Ascaris, testis of salamander. 
Thirteenth Day, Reduction divisions: Objects, oviducal eggs of 
Diaptomus, uterine eggs of Thysanozoon, laid eggs of Cyclops. 
Fourteenth Day, Fertilization of the metazoon egg: Objects, living 
eggs of Diplogaster and Rhabditis, eggs of sea urchin, uterine eggs 
of Ascaris. Fifteenth Day, Fertilization, further facts and theories : 
Objects, bastard larve of sea urchin, Antherozoids of the Fern, 
bastard larvæ of Echinus and Sphezrechinus (including Boveri’s 
famous experiment on the fertilization of enucleated eggs), results 
of crossing white mice with the Japanese house mice. Sixteenth 
Day, Cells of the germ tracks: Objects, uterine eggs of Ascaris, 
eggs of Cyclops brevicornis. 
The subjects considered show that the field is well covered, while 
the objects taken up for study on some of the days would indicate 
that the “day” is to be interpreted in the Biblical sense. The most 
notable omission from the practical work is the whole subject of the 
cleavage of the egg, in which are illustrated, as perhaps nowhere else, 
the various kinds of cell division (equal, unequal, differential, etc.), 
the mechanics of cell division, experimental modifications of cleav- 
age, and the promorphology of the ovum. These subjects are briefly 
