MUSEUM OF COMPARATIVE ZOOLOGY. 77 



lateral and of median buds. From around eacli of the lateral buds, in 

 like manner, both lateral and median buds of a higher order arise. But 

 from each of the median buds only median buds arise. These median 

 buds, are not, however, all of the same kind. The one first produced (a *, 

 of Formula 7, ^- of Form. 8) differs from all formed after it (b *, c *, d *, 

 etc.) in this, that it bears no polypide, but forms the tip of a stolon 

 from which both median and lateral buds arise (/3, a, near extreme right of 

 Form. 8). From the second and all succeeding median buds (a b, c, etc.. 

 Form. 8), there arise only median buds of a still higher order. Of the 

 latter, the first, as before, produces no polypide, but becomes the tip of a 

 stolon giving rise to both median and lateral buds ; the others give rise 

 to only median buds of a still higher order, and so on. Our former for- 

 mula assumed that all median buds were alike, and all incapable of giving 

 rise to lateral individuals. Their dissimilarity introduces a complication, 

 so that the species must be represented by some such formula as 

 this ^ : — 



(8) 



• a** * ai * * 



* * • . 



^D * -^;- C * a * l';l- B * b * a * -I-Jo * A * c * b * ^-I- a * i3 » a*^^fi*ita* o^ • -$- 



* * » ♦ 



♦ ■$■ • * oi • 



• a*» •oi* • 



* a -ijj 

 etc. etc. 



1 It must be borne in mind that such a graphic representation as this, while it 

 agrees with the descriptions and figures of Kraepelin and Hincks ('80, Plate 79) so 



