You know what hemisphere you'll be in when you leave?
The foot now protrudes below the mouth, and the post-oral hemisphere of the trochosphere grows more rapidly then the anterior or velar area.
The whole story points to a general distribution of flowering plants from the northern hemisphere southwards.
The Glossopteris flora gradually spread to the northern hemisphere and intermingled with the later Palaeozoic flora which still persisted.
As a rule the genera of the northern hemisphere differ from those of the southern.
They point to cooler conditions in the northern hemisphere: palms and tropical types diminish; deciduous trees increase.
A well-marked trochosphere is formed by the development of an equatorial ciliated band; and subsequently, by the disproportionate growth of the lower hemisphere, the trochosphere becomes a veliger.
The typical genus Lilium and Fritillaria are widely distributed in the temperate regions of the northern hemisphere.
Fagus, starting from the northern hemisphere, has more than held its own in Europe and Asia, but has all but died out in North America, finding conditions favorable for a fresh start in Australasia.
Most stations in the northern hemisphere have a conspicuous maximum at midsummer with little thunder in winter.
In the southern hemisphere the Palaeozoic flora appears ultimately to have been profoundly modified by a lowering of temperature and the existence of glacial conditions over a wide area.
Though now on the way to extinction, Cycadeae are still widely represented in the southern hemisphere by genera which, however, have no counterpart in the Mesozoic era.
The monotypic Pringlea antiscorbutica, the Kerguelen Island cabbage, has no near ally in the southern hemisphere, but is closely related to the northern Cochlearia.
It has a world-wide distribution, but finds its chief development in the temperate and frigid zones, especially of the northern hemisphere, and as Alpine plants.