ivith some Remarks ou the N^ature of the Spongioe Marinte. 399 



those of the Ectospermn ; from its germination and subsequent manner of 

 growth being" precisely similar to those exhibited by many of the lower 

 plants ; from the general resemblance of its transparent membrane or cuticle 

 to that of the leaves of plants; from its jelly or parenchymatous substance 

 being composed of globules; from the chromule contained in them giving a 

 permanent colour to paper; from the effects of acids upon its whole sub- 

 stance, and green colour; from its total want of irritability and sensation; 

 from its not being polypiferous ; from possessing no trace of any animal or- 

 ganization ; and from its receiving nutriment from the water alone, — have ren- 

 dered me no longer doubtful. 



In conclusion, you will permit me to add a few general remarks on the 

 nature of the Sponghe Mavince, avoiding at the same time as much repetition 

 of my preceding observations as the subject itself will allow. 



Considering that these remarkable substances, which have so long puzzled 

 authors in their endeavours to assign to them a proper station in the classi- 

 fication of the various works or productions of nature, were composed of a 

 fibrous unorganized skeleton, generally strengthened by spicula, and formed 

 by secretion from a soft parenchymatous substance or jelly, which in fact 

 constituted the individual animal ; that this animal-jelly was endowed, ac- 

 cording to several naturalists, with some slight symptoms of sensation and of 

 contraction and dilatation, and possessed the powers of sucking in and throw- 

 ing out the sea-water by a sort of inspiration and expiration, I therefore in- 

 stituted for them an order, which I termed Gelathiifera*, in purpose to 

 express this view of the animal or live jelly. For in the summers of 1822 and 

 1823 many observations on some specimens of Spongia oculata and 6'. urens, 

 in their native localities on the coast of Durham, convinced me that they 

 were in truth not polypiferous ; but I was then unable to prove with any 

 satisfaction to myself tlie contractile and expansive faculties, which I was 



* Dr. Grant has lately placed the Sponges in an order Porifera. But I must here observe, that in 

 my " Natural History of the Vicinity of Stockton on Tees," -which was written in the spring of 1825, 

 printed in 1826, and published in 1827, I formed my 4th order of Polypnria "Porifera," to com- 

 prise the genera Cellepora, Millepora, and Tubidiporu. And 1 have in a former note stated that my 

 order 8. Gelathiifera comprehends the Sponges. 



VOL. XVJII. 3 G 



