A CHAT ON SCIENCE

Hokitika Guardian, 15 August 1924, Page 1

A CHAT ON SCIENCE

( O-OPKRATIO.X fX LOW LIFF

(My Dr F'.dwin K. Slosson, Director Science. WashingtonL

Till, more we learn ol nniiiml nml plant life the less it seems like it eltaos of iueessaiH eimllict and carnage. 'I lie struggle lur exi-teme is real. Will' to the death, to the strongest belong the spoils, everyone fur liini-clt, tin* weak to the wall, and all that, lint also we ti lid mi closer inspection more than we thought of mninal aid. not only bct ween individuals of tin- same family, or pack, i r species, hnt helween species ol Ihe most widely dillerent sorts. told sometimes it. turns out tlint wlmt sums to he inveterate enemies are actually involuntary allies. .Many an animal owes his success in lile to the unrecognised co-operation ol the humblest creatures. For instance, it is a (>reat advantage for lislies and other marine forms to have a lighting svslein fee i|se at night. and in the depths of the sea. Seme have elands that secrete the two kinds of chemical* that produce light when mixed. Jittt many o’hers depend upon luminous bacteria, of which some thirty species are known. These live in certain elands, or stream through tithes, which serve as lamps to the lost. Ihe cuttlefish has gone so lar as to fix np a reflector behind and a lens in front of its light-giving edoiiy ol bacteria. In the glow-worm the bacteria are also present in the battle's eggs, which are likewise Inmitmns. I hut eria and other mil rn-organism* are ol ten found aiding digestion by attacking snhstaiiees that tlicit; hosts would lind too lough (o tackle alone. Vegetable foods, for instance, contain more or less cellulose, wood fibre, which is extremely indigestible stuff. and even cattle could n«t get nutriment out of it if it were not for a process of internal fermentation. The so-call-ed -‘white ant-." termites, terror of the tropics, (jet their living liv eat inn the in-idcs out of furniture and hanks, yet they cannot digest such cellulose. What they do is to chew it up. and turn it. over to I unci, which thrive on it. and then the termite- feed on the I'lingi. Flies lay their ecus in meat, hut the larvae when they hatch out cannot digest the meat without the help of the bacteria in their 'intestines. l’cas. beans, and alfalfa owe tlieir power of utilisin'; the nitrogen of the air to the bacteria that colonise on their roots ill the form of nodules. Most (limits cummi use free nitrogen. hut have, it served up to them in the form of salts, such a- nitrates. The root nodules therefore might he called the muscle shoals of the plant world, hut that would nut he a fair name for tliem. since they are working. The tubers of the potato are due to a parasitic fiinpit-. Potato seeds planted in sterilised soil do not produce tubers, hut when the fungus is allowed to invade the soil tuliers start to “row. If you should ask a young potato plant whether it wanted to la- infected by a fungus, and if the potato were as intelligent—or rather, as unintelligent as men are—it douhtle.-s would reply that its pristine purity must'remain unimpaired by any parasite. Vet that refusal would deprive the plant of its chance of perennial life, and what’s worse.deprive us cf potatoes. It has been found that orchid seeds do not sprout unless a certain fungus is present. and each specie's of orchid lias to have its particular species of fungus.

The lichen of a tree or -Cents to us a ‘piitplo single growth, hut it really is a partnership of two very dissimilar forms of vegetation, a plant and a parasite, an alga and a fungus. Which is to be regarded its the host, and which the parasite, which was originally- the patient and whielt wits the disease, can hardly he determined, ssiice the relation varies in different lichens, and the two strange associates have becu living together so long now that they play into each others hands, and could hardly stand it to live alone.

iso it happen* that a plant or animal gets used to a chronic disease, and finds it advantageous, and a parasite that came, to prey remains to serve. Dr Nuttall. of Cambridge, who at the Liverpool meeting of the Dritish Association for tlfe Advancement of Science

gave these ami many other instances of co-operation, of symbiosis its biologists call-it; thinks that they all began as cases of parasitism, but that the conflict between the associated organisms ended in mutual adaption. The two enemies become allies, and the parasite becomes a partner,