FRESH WATER POLYPE (HYDRA) 



PLATE X 



Fig. I flvctra, 



or Common. Hydra. 



Ifiy 



. 2 Hydra fo 



iffL B\&quot;dryj. 



I. Longitudinal Section 

 f Hydra. 



Tentacles 



Fid. 3 CdU oi~ihe Ectoderm. 



Q 



l^udais.. 



-Jffouth 



NtmaiotystfS- 



J^cto dfs~rn 

 ErLdocLerrn,- 



SpeTtnatffxoc 



C Segmented avnjn,so-caUed, eyQ 



K - Tnbryo cells 



Diagram 2. -Development of Hydrozoa 



&. Section, ff flanula. 



b .Section, of Mo 



\Ga~minal spot 



EARTH-WORM (LUMBRICUS TERRESTRIS) 



Fig Z._ThefiTieen Anterior Segments -Ventral aspect 



Anus 



Fig I. 



Mouth 



flpenznq of Vas 



WlA.KJohn*ion. Edinburgh 4 London. 



