MUSEUM OF COMPAKATIVE ZOOLOGY. 77 



lateral and of median buds. From around each 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, «!J- 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 (p, 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 biads 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 1 : — 



» * ♦ » 



* * * « » 



* * oi ♦ * Oi • 



b * * /8 * 



(8) ^- 



« » 



* a* a * a * 



* a 



* a » • 



» -^ 



* tti » 



a-^ * 



* » » « 



^D * <4 C * a * ;|J B * b * a * -^Kfl * A * c * b * ^ a * j3 * o * ^ ■!■> /8 » -^;- o ♦ a^ 



* 



* ay * 



* * ai' 



a ^ 



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 



