19 bowling, i.e. playing bowls.
schoolmen: the theological and metaphysical writers of the middle ages.
Cymini sectores: 'splitters of cumin-seed,' i.e. what we should call 'hair-splitters,' the seed of the cumin (a plant something like fennel) being very minute.
20 In the universality of the kind, etc.: i.e. the race endures, the individual perishes.
24 Lycosthenes, a German scholar of the sixteenth century, wrote a commentary on a book of Lives of eminent men, a work attributed to Pliny the younger (first century A.D.).
26 The eighth climate: i.e. England, which lies in the eighth of the zones (or 'climates') into which the old geographers divided the globe.
constellated: i.e. born under a particular 'constellation' or conjunction of planets (an astrological expression).
Hydra: the many-headed monster slain by Hercules.
in casting account=in doing sums.
27 Doradoes=rich men; a Spanish word, as in the phrase 'El dorado' ('the rich country').