368 GENERAL HISTOEY OF THE INFUSORIA. 



The history of the metamorphoses of Trklioda Li/ncens recounted bj' M. 

 Jules Haime {Ann. d. S. N. 3 ser. xix. p. 109) calls for notice in this place, 

 although we are not disposed to assign it much value, inasmuch as some 

 of the phenomena stated are very extraordinaiy, are unsupported by any 

 parallel facts, and are in actual opposition to those best ascertained respect- 

 ing the organization and functions of the Ciliata. We would especially direct 

 attention to the statement of the exudation of sarcode, and the consequent 

 reduction of size, as a necessary step in the developmental phases, — an occur- 

 rence, in oiu- belief, without analogy and quite anomalous. 



He first asserts that '' O.vijt ri cha (Ehr.) is a laiTal phase of Triclioda Lyn- 

 ceus, and next that, on its fissiparous di\ision, generally one of the two seg- 

 ments produced assumes a globular form, losing almost all its a23pendages, 

 both cilia and setas, and, at the same time, gives exit to successive portions 

 of its sarcode, so that vacuoles multiply in its interior. At this stage a ge- 

 latinous cyst is excreted around it which ultimately hardens into a mem- 

 branous envelope. In a short time the contents of the cyst shrink from the 

 cyst-walls and leave a space around them, when ciliary movement appears 

 at one part, and, a further escape of granular sarcode having taken place 

 through the cyst- wall, the figure becomes more or less modified. Two por- 

 tions are now distinguishable within the cyst — a ciliated embiyo and a mass 

 of efiete granular matter ; and, as time elapses, the former seems to grow 

 at the expense of the latter, and eventually makes its escape from the nearly- 

 emptied cyst. The freed animalcule is not at first very diff'erent in appearance 

 from the parent Oxytricha, although only about two-thirds its diameter ; but 

 ere long it developes itself into a veiy difi'erent l)eing. In so doing, it first 

 exudes some more of its substance, then produces numerous short stiff" setae 

 to serve it as feet, acquires a hard integ-umcnt in the form of a shield, or 

 carapace, and forms a mouth, in the form of a slit on one side, and, in front 

 of this, a gyrating filament to produce a current for the introduction of 

 food. In this transformed being the Aspidisca (Ehr.) is recognizable, having 

 a very much smaller size than the original Oxytriclia. The reversed course 

 of development, viz. that of Aspidisca into O.vytricha has not been fol- 

 lowed ; but it may be conjectured that a sexual process is interposed, pro- 

 bably in connexion with other metamorphoses." 



Before taking leave of the subject of reproduction among the Ciliata, it 

 is important to add a statement made by Lachmann in his excellent and 

 oft-quoted essay (p. 239). He writes — " With regard to the peculiar pro- 

 cess of copulation or zygosis of the Infusoria, as its object is still entirely 

 unknown, I shall only state that, except in the Diatomacece and Desmidiacece, 

 the position of which is still doubtful, it has hitherto been observed par- 

 ticularly in Actinophrys and Acinetina. According to an oral statement, 

 E. Claparede has also seen Vortkellina (especially V. microstoma) in zygosis ; 

 and I have twice met with double animals of Carcliesium, still sitting upon 

 a double stalk and constantly becoming more amalgamated, so that the 

 cavities of both the fused animals communicated, and the morsel which was 

 passed from the pharynx of one animal usually ascended in the cavity of 

 the other, up to the lower surface of its ciliary disk. The rotatory organs 

 remained separate ; and after the lapse of some time, the double animal cast 

 itself loose from the stems, and swam about for more than twenty-foui' hours 

 by means of a circlet of cilia, which was produced around the rounded hinder 

 extremity formed by the coalescence of the two posterior extremities of the 

 individual animals." 



Nature or the Ciliated Protozoa. Their Existence as Independent 

 Organisms. Cell Theory applied to them. — That the bein2:s we have com- 



