KNOWLEDGE. 



[January 2, 1899. 



a labourer in the field of cryptopamic botany, and the 

 specific name describing the bladder-like form of the 

 principal part of the structure. This species is not un- 

 common, and is to be found on stumps and logs of decaying 

 wood. 



The bladder-shaped vessels which we have spoken of 

 are the spore cases of the organism, i.e., they are cases in 

 which the spores are stored, much as seeds are stored in a 

 seed vessel. They are known as ajwrangia. We have 

 chosen to begin with the organism in this form because 

 it is the most conspicuous, and therefore the most easy 

 for a beginner to get hold of. 



If now a specimen of this Badhamia be placed under the 

 microscope, it will be seen that the coat of the sporangium 

 is a delicate shell containing minute granules of lime, and 

 that the dark appearance of the body is due to the brown 

 spores which lie beneath the transparent shell. Next if a 

 sporangium be broken and the contents examined under 

 the microscope (as shown in Fig. 2), it will be found that 

 the delicate white shell contains a network of threads, 

 also white from the lime with which they are charged, and 

 that they occupy the interior of the sporangium, and pass 

 from wall to wall much like the cancelli in a long bone. 

 In addition to these threads there are the small round 

 spores. In these threads we have come upon a very 

 characteristic structure in these little organisms ; it is 

 found in the sporangia of most of them but in very 

 varying forms, and very diversely arranged, of which we 

 shall say more hereafter. This system of hairs in the 

 sporangia is known as the cupillitium. 



%■■ 



_J.^. 



life and motion ; they seem at once wilful and purposeless ; 

 they gambol with one another, and their frolics remmd 

 one of young lambs in spring. They are capable not 

 only of motion but of digestion, and of the capture of food 

 in a manner to be hereafter described. These little pieces 

 of protoplasm bear several names, and as the variety of 

 phraseology is apt to puzzle students, we pause to say 



Fig. 2. — Badhamia ntrirularis, broken Sporangia 

 9liowing Capillitium. 



As the sporangia contain spores it will be at once under- 

 stood that we stand on the threshold of a new genera- 

 tion, and we must now follow the history of the spores. 

 These, when carefully looked at, are seen to be covered 

 with minute spines, and thus present a somewhat rough 

 appearance. 



If now the spores be placed under favourable circum- 

 stances, i.e., with sufficient moisture and warmth, small 

 translucent bits of naked protoplasm will be seen to 

 emerge from them, leaving a mere shell behind them ; 

 these bits of protoplasm have a movement of their 

 own in the water, and can be seen both to shake 

 themselves, and to move forwards ; they push out a part of 

 their protoplasm as a whip or flafjellum at one end of the 

 body, swimming with this in front of them, the whip 

 having a sort of lashing movement. Fig. 3 exhibits 

 some of these bits of protoplasm. Their motions are 

 particularly amusing to watch; they swim, they wriggle, 

 they revolve, tbey fhake themfelves, they are full of 



l u i i l.1 , .1 



1 JO a 



X 1200 



\. — Swarm Spore of StemonUis fusca of the usual form ^lien 

 swimmmg. 7j. Nucleus ; v. Vacuoles. 



2. — Swarm Spore with three Bacilli adhering to expanded posterior 

 extremitj. 



3. — A Swarm Spore with delicate pseudopodia, to one of which 

 a Bacillus is attached. 



4 —The same Swarm Spore. The Bacillus ui the act of being 

 drawn in and partly invested with a tube-like extension of the body 

 surface. 



5. — The same Bacillus contained in a long vacuole, and bulging 

 out the sides of the Swarm Spore. 



6. — The same Bacillus bent double after violent jerking move- 

 ment of the Swarm Spore. 



(From Journ. Linn. Society, Sofani/, Vol. 2.'j. p. 44.0, by permission 

 of the Linnean Society and Mr. Lister.) 



that they are called sometimes swarm spores, or swarm 

 cells, sometimes zoospores, and as individual pieces of 

 protoplasm they are sometimes called protoplasts. The 

 spore of a moss, or of a fern, is a small structure, endowed 

 with no power of motion ; these swarm spores, as we have 

 seen, have a power of motion ; the spore of the moss, or 

 the fern, is capable by itself of reproducing the plant from 

 which it has come, but these swarm spores are only repro- 

 ductive after fusion with others, as we shall hereafter see. 

 The name swarm cell is likely to mislead, because the 

 thing so called is protoplasm without any containing 

 wall, and therefore does not answer to the notion of a cell 

 as it exists in a beehive or in a police station. We shall 

 therefore speak of them as nvarm spores, though even 

 that name seems to us to be far from felicitous. 



The next step in the life of these swarm spores is that 

 they rapidly increase by bi-partition, i.e., splitting into two 

 parts. An occasional phenomenon here sometimes inter- 

 venes. At times the swarm spores assume a globular form, 



