DEDIFFERENTIATION IN PEROPHORA 691 
1. Clavellina. A=zooid, B=stolon. 
(a) Normal, (b) Reduced, 
A A’ 
v V 
(B) (B’) 
2. Perophora. A=zooid, B=stolon. 
(a) Normal, (6) Starved, water (c) Starved, water 
changed, not changed, 
A A pe 
Y : t 
(B) TEL B+ 
3. Planaria or single Stenostoma zooid. A=brain-region, B= 
pharynx-region, C = tail-region. 
(a) Normal, (6) After decapitation. (c) Subsequent regeneration, 
A / 
y B 
(B) | (B) 
y (C) v 
(C) (C) 
4. Stenostoma chain. A=brain-region, B=rest of zooid. 
A, B,=oldest, A, B,= youngest zooid. 
(6) Transection giving brain-region 
behind posterior brainless region (c) End-result 
(a) Normal. of another zooid., from (b), 
fe (B 1) ) 85) 
(B_1) A3 ong 
iat. ) (Bs) 
( E - (d) Transection giving older 
i( he \\ zooid posterior to younger, (e) Result of (d). 
Bz 
( A 4+ (" 3 ) AS 
ay , 
(e")} a) Bs 
(A (A 2 | 
((B"2) J liB"e) 
5. ‘Spinal man.’ A=cerebral centres, B= mass-reflex. 
(a) Normal, (b) After transection of cord, 
A 
Ah B 
(B’) 
6. Mental regression. A=adult system, B=juvenile system, 
C= infantile system. (Only three systems given for simplicity’s sake.) 
(a) Normal. (b) After regression. (c) During recovery, 
A ——e —— 
( A A | 
(B’) \ es 
y (B’) f 
(C’) ae ca B 
i v 
C (C’) 
