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rganism…hands or feet or any other physical attribute。 So we can take an unknown piece of DNA and determine roughly； by puter； where it fits in the evolutionary sequence。 It's time…consuming； but it can be done。〃
〃And the other way？〃
Wu shrugged。 〃Just grow it and find out what it is；〃 he said。 〃That's what we usually do。 I'll show you how that's acplished。〃
Tim felt a growing impatience as the tour continued。 He liked technical things； but； even so； he was losing interest。 They came to the next door； which was marked FERTLIZATION； Dr。 Wu unlocked the door with his security card； and they went inside。
Tim saw still another room with technicians working at microscopes。 In the back was a section entirely lit by blue ultraviolet light。 Dr。 Wu explained that their DNA work required the interruption of cellular mitosis at precise instants； and therefore they kept some of the most virulent poisons in the world； 〃Helotoxins； colchicinolds； beta…alkaloids；〃 he said； pointing to a series of syringes set out under the UV light。 〃Kill any living animal within a second or two。〃
Tim would have liked to know more about the poisons； but Dr。 Wu droned on about using unfertilized crocodile ova and replacing the DNA； and then Professor Grant asked some plicated questions。 To one side of the room were big tanks marked LIQUID N2。 And there were big walk…in freezers with shelves of frozen embryos； each stored in a tiny silver…foil wrapper。
Lex was bored。 Nedry was yawning。 And even Dr。 Sattler was losing interest。 Tim was tired of looking at these plicated laboratories。 He wanted to see the dinosaurs。
The next room was labeled HATCHERY。 〃It's a little warm and damp in here；〃 Dr。 Wu said。 〃We keep it at ninety…nine degrees Fahrenheit and a relative humidity of one hundred percent。 We also run a higher O2 concentration。 It's up to thirty…three percent。〃
〃Jurassic atmosphere；〃 Grant said。
〃Yes。 At least we presume so。 If any of you feel faint； just tell me。〃
Dr。 Wu inserted his security card into the slot； and the outer door hissed open。 〃Just a reminder： don't touch anything in this room。 Some of the eggs are permeable to skin oils。 And watch your heads。 The sensors are always moving。〃
He opened the inner door to the nursery； and they went inside。 Tim faced a vast open room； bathed in deep infrared light。 The eggs lay on long tables； their pale outlines obscured by the hissing low mist that covered the tables。 The eggs were all moving gently； rocking。
〃Reptile eggs contain large amounts of yolk but no water at all。 The embryos must extract water from the surrounding environment。 Hence the mist；〃
Dr。 Wu explained that each table contained 150 eggs； and represented a new batch of DNA extractions。 The batches were identified by numbers at each table： STEC…458/2 or TRIC…390/4。 Waist…deep in the mist； the workers in the nursery moved from one egg to the next； plunging their hands into the mist； turning the eggs every hour； and checking the temperatures with thermal sensors。 The room was monitored by overhead TV cameras and motion sensors。 An overhead thermal sensor moved from one egg to the next； touching each with a flexible wand； beeping； then going on。
〃In this hatchery； we have produced more than a dozen crops of extractions； giving us a total of two hundred thirty…eight live animals。 Our survival rate is somewhere around point four percent； and we naturally want to improve that。 But by puter analysis we're working with something like five hundred variables： one hundred and twenty environmental； another two hundred intra…egg； and the rest from the genetic material itself。 Our eggs are plastic。 The embryos are mechanically inserted； and then hatched here。〃
〃And how long to grow？〃
〃Dinosaurs mature rapidly； attaining full size in two to four years。 So we now have a number of adult specimens in the park。〃
〃What do the numbers mean？〃
〃Those codes；〃 Wu said； 〃identify the various batch extractions of DNA。 The first four letters identify the animals being grown。 Over there； that TRIC means Triceratops。 And the STEC means Stegosaurus； and so on。
〃And this table here？〃 Grant said。
The code said XXXX…0001/1。 Beneath was scrawled 〃Presumed Coelu。〃
〃That's a new batch of DNA；〃 Wu said。 〃We don't know exactly what will grow out。 The first time an extraction is done； we don't know for sure what the animal is。 You can see it's marked 'Presumed Coelu；' so it is likely to be a coelurosaurus。 A small herbivore； if I remember。 It's hard for me to keep track of the names。 There are something like three hundred genera of dinosaurs known so far。〃
〃Three hundred and forty…seven；〃 Tim said。
Grant smiled； then said； 〃Is anything hatching now？〃
〃Not at the moment。 The incubation period varies with each animal； but in general it runs about two months。 We try to stagger hatchings； to make less work for the nursery staff。 You can imagine how it is when we have a hundred and fifty animals born within a few days…though of course most don't survive。 Actually； these X's are due any day now。 Any other questions？ No？ Then we'll go to the nursery； where the newborns are。〃
It was a circular room； all white。 There were some incubators of the kind used in hospital nurseries； but they were empty at the moment。 Rags and toys were scattered across the floor。 A young woman in a white coat was seated on the floor； her back to them。
〃What've you got here today； Kathy？〃 Dr。 Wu asked。
〃Not much；〃 she said。 〃Just a baby raptor。〃
〃Let's have a look。〃
The woman got to her feet and stepped aside。 Tim heard Nedry say； 〃It looks like a lizard。〃
The animal on the floor was about a foot and a half long； the size of a small monkey。 It was dark yellow with brown stripes； like a tiger。 It had a lizard's head and long snout； but it stood upright on strong hind legs； balanced by a thick straight tail。 Its smaller front legs waved in the air。 It cocked its head to one side and peered at the visitors staring down at it。
〃Velociraptor；〃 Alan Grant said； in a low voice。
〃Velociraptor mongoliensis；〃 Wu said； nodding。 〃A predator。 This one's only six weeks old。〃
〃 I just excavated a raptor；〃 Grant said； as he bent down for a closer look。 Immediately the little lizard sprang up； leaping over Grant's head into Tim's arms。
〃Hey！〃
〃They can jump；〃 Wu said。 〃The babies can jump。 So can the adults； as a matter of fact。〃
Tim caught the velociraptor and held it to him。 The little animal didn't weigh very much； a pound or two。 The skin was warm and pletely dry。 The little head was inches from Tim's face。 Its dark； beady eyes stared at him。 A small forked tongue flicked in and out。
〃Will he hurt me？〃
〃No。 She's friendly。〃
〃Are you sure about that？〃 asked Gennaro； with a look of concern。
〃Oh； quite sure；〃 Wu said。 〃At least until she grows a little older。 But； in any case； the babies don't have any teeth； even egg teeth。〃
〃Egg teeth？〃 Nedry said。
〃Most dinosaurs are born with egg teeth…little horns on the tip of the nose； like rhino horns； to help them break out of the eggs。 But raptors aren't。 They poke a hole in the eggs with their pointed snouts； and then the nursery staff has to help them out。〃
〃You have to help them out；〃 Grant said； shaking his head。 〃What happens in the wild？〃
〃In the wild？〃
〃When they breed in the wild；〃 Grant said。 〃When they make a nest。〃
〃Oh； they can't do that；〃 Wu said。 〃None of our animals is capable of breeding。 That's why we have this nursery。 It's the only way to replace stock in Jurassic Park。〃
〃Why can't the animals breed？〃
〃Well； as you can imagine； it's important that they not be able to breed；〃 Wu said。 〃And whenever we faced a critical matter such as this； we designed redundant systems。 That is； we always arranged at least two control procedures。 In this case； there are two independent reasons why the animals can't breed。 First of a they're sterile； because we irradiate them with X…rays。〃
〃And the second reason？〃
〃All the animals in Jurassic Park are female；〃 Wu said； with a pleased smile。
Malcolm said； 〃I should like some clarification about this。