10-1 SUMMARY OF CURRENT RESEARCHES RELATING TO 



which after 2-3 days led to a reascent. (d) Movements in the water due 

 to wind caused the Sphterozoa to sink. The direction of the wind, e. g the 

 sirocco, had a marked influence which is discussed in detail. Certain 

 currents also influenced the distribution to a noteworthy extent, (e) Dr. 

 Brandt's observations are on the whole against any periodicity in the 

 development of the Sphserozoa. (5) The geographical distribution, the 

 derivation of these forms from the Atlantic, their absence in colder seas, 

 &c., are then discussed. (6) Phosphorescence. The Sphserozoa are phos- 

 phorescent, but not with great intensity. The central portion alone is 

 illuminated. The oil-globules are regarded as the seat of the process. 

 (7) Parasites and " Inquilinen." Colonies of Myxosphaera cserulea fre- 

 quently contained a parasitic amphipod, Hyper ia, also Copepods, and 

 Appendicularise ; living diatoms also occurred in young Collozoa. 



III. Development and Beproduction. — (1) Division of the colony seems 

 certainly to occur, but Brandt was not able to observe the mode of forma- 

 tion of CoUozoum chains supposed to occur by Hackel and Hertwig. 

 (2) Division of the individuals was observed only in young vegetative 

 colonies, and not in the older or in reproductive forms. (3) Swarm-spore 

 formation, (a) Isospores. Hertwig's observations are generally corrobor- 

 ated, the main diiference consisting in Brandt's denial of the statement that 

 the whole mother organism is resolved into the spores. The greater part 

 of the cortical substance is left behind and breaks up. The isospores of 

 all Sphaerozoa are said to have two flagella. (b) The formation of an 

 isosjwre is distinguished from the above by the occurrence of groups of 

 nuclei in the individuals, by the differentiation of the nuclei, and by the 

 distinct macrospore and microspore nuclei. The anisospores differ further 

 in their more or less bean-like shape, in their difference of size, in the 

 character of their nuclei, and in the absence or peculiarity of crystals. The 

 anisospores have much less reserve material than the isospores. The 

 extracapsular changes are essentially similar. The cortical substance again 

 breaks up, the yellow cells persist as before, (c) Alternation of generations. 

 According to Brandt all the Sphserozoa have the above two modes of repro- 

 duction. In seven out of ten species the twofold method has been demon- 

 strated. The Sphserozoa exhibit an alternation of generations as in algse 

 and fungi. He believes that from the union of the sexually dimorphic 

 anisospores, a fused mass will result which will produce isospores. He 

 has not, however, observed the conjugation of the anisospores. (4) Extra- 

 capsular bodies only occur in young colonies, which contain a few indi- 

 viduals. They always exhibit a more or less striking resemblance to the 

 incipient stages in the intracapsular formation of anisospores. They arise 

 by budding from the individuals, are refractive and without granules, but 

 often with an oil-globule, usually with a fatty-mass, and always with a 

 nucleus. True extracapsular bodies have not been observed in CoUo- 

 sphaeridfe, but in young forms a somewhat similar phenomenon occurs. 

 In some cases these budded bodies are normally modified into anisospores. 

 In other cases they simply become individuals. In Cullosphaerids this 

 reproduction within the young forms always results in rapid multiplication 

 of the individuals; in Sphjerozoa, anisospores sometimes are formed, though 

 it is quite likely that in the latter also the extracapsular bodies may often 

 form individuals. (5) Development. Five phases in the life-history are 

 distinguished: — (i,) the swarm-spore, (ii.) the young vegetative phase, 

 (iii.) the young reproductive phase with formation of extracapsular bodies, 

 (iv.) the older vegetative phase, (v.) the older reproductive phase with 

 formation of isospores and anisospores. In the vegetative phases the nuclei 

 are homogeneous and simi)ly refractive ; in the reproductive they are dis- 



