418 EEYIEWS. 



It should be remembered, however, that much which is now 

 known of the structure of the lower animals had, at the time of 

 Cuvier, been very imperfectly acquired, and that many of the im- 

 provements in classification for which he had prepared the way waited 

 only to be revealed by the clearer light of subsequent anatomical 

 discoveries. 



Thus many investigators have agreed to transfer the class Intes- 

 tina to the Articulate sub-kingdom (preferably known as Annullosa). 

 Here, also, have been placed the Eotifera, by Cuvier associated with 

 the Infusoria. 5 



So, likewise, the class of animals now known as Polyzoa or Bryo- 

 zoa, whose several forms Cuvier had distributed among the Polypi r 

 has been since removed to the sub-kingdom Mollusca. 6 



The Sponges were by Cuvier regarded as animals and classed with 

 the Polypes, a view of their affinities which some Zoologists still 

 continue to hold. 7 Most, however, are disposed to place the Sponges* 

 Infusoria,, and other organisms of like structure subsequently disco- 

 vered, in a group distinct from the remaining Zoophyta. Thus 

 Milne Edwards (first excluding the Intestina, Eotifera, and Polyzoa) 

 has arranged the other Zoophyta under two. groups, 8 as follows : — 



ZOOPHYTES. 



Classes. 

 Radiaires ( Ecmnodeemes 



OU < ACALEPHES 



A. rayonnes. ( Polypes. 



Sareodaires. \ skhhhaiem. 



The Sareodaires are now more generally considered as a distinct 

 &ub-kingdom, under the name of Protozoa. 9 So that the sub-kingdom 



tion, but also a certain degree of development, — a condition which can only be 

 required of the single classes. The consequence is, that all the animals of low 

 organization are thrown among the Kadiata, although very many of them are by no 

 means radiate in their structure. The boundaries under these circumstances could 

 only be drawn arbitrarily." 



5 Milne Edwards, in 1838, clearly pointed out the necessity for effecting these 

 changes. Vid. Ann. S. N., Ser. 2, Tom X. p. 194. 



6 For a concise account of the several steps of this transference consult Alhnan, 

 Fresh-water Polyzoa, p. 2 ; and Busk, A. N. H., 1852, Ser. 2, Vol. X. p. 352. 



7 Van Beneden et Gervais, and R. Leuckart, writing in 1859, appear to give it 

 their sanction - 



8 Cours Elementaire d' Histoire Naturelle — Zoologie. — The above has been 

 copied from the eighth edition, 1858. 



9 Siebolcl, Lehrbueh der vergleichenden Anatomie — Wirbellose Thiere — 1845. 

 But the term Protozoa may be found in the works of older writers, and appeal's to 

 have been first used by Goldfuss, in his Handbuch der Zoologie, 1820. 



